The Stoneflies (Plecoptera)
of the Pacific Northwest
By
STANLEY G. JEWETT, JR.
U.S. Bureau of Commercial Fisheries
Portland, Oregon
OREGON STATE COLLEGE
CORVALLIS, OREGON. PRINTED
AT THE COLLEGE PRESS, 1959
OREGON STATE MONOGRAPHS
Studies in Entomology
Number 3
Published by Oregon State College
Corvallis, Oregon
1959
Table of Contents
Page
iii
iv
Table of Contents
List of Illustrations
Introduction
Life History
1
The Adult
The Egg
2
2
6
The Nymph
7
Distribution
Preservation and Collecting
Systematic Treatment
8
9
10
List of Stoneflies of the Pacific Northwest
Key to the Families and Genera of the Stoneflies of Pacific Northwestern United
States (Adults)
Key to the Families and Genera of the Stoneflies of Pacific Northwestern United
States (Nymphs)
Family Peltoperlidae
Key to the Subgenera and Species of Pacific Northwest Peltoperla (Males and, in
part, females)
Key to the Subgenera and Species of Pacific Northwest Peltoperla (Nymphs)
Family Nemouridae
Subfamily Nemourinae
Key to the Subgenera and Species of Pacific Northwest Nemoura (Males)
Key to the Subgenera and Species of Pacific Northwest Nemoura (Females)
Subfamily Leuctrinae
Key to the Subgenera and Species of Pacific Northwest Leuctra (Males)
Key to the Subgenera and Species of Pacific Northwest Leuctra (Females)
Key to the Subgenera and Species of Pacific Northwest Leuctra (Nymphs)
Key to the Species of Pacific Northwest Megaleuctra (Males)
Key to the Species of Pacific Northwest Perlomyia (Males)
Key to the Species of Pacific Northwest Perlomyia (Females)
Subfamily Capniinae
Key to the Species of Pacific Northwest Capnia (Males)
Key to the Species of North American Eucapnopsis (Males)
Key to the Species of North American Eucapnopsis (Females)
Key to the Species of Pacific Northwest Isocapnia (Males)
Subfamily Taeniopteryginae
Key to the Subgenera and Species of Pacific Northwest Brachyptera (Males, and
females by color)
Family Pteronarcidae
Key to the Genera and Species of Pacific Northwest Pteronarcidae (Males)
Key to the Genera and Species of Pacific Northwest Pteronarcidae (Females)
Family Perlodidae
Key to the Subgenera and Species of Pacific Northwest Arcynopteryx (Males and,
in part, nymphs)
Key to the Subgenera and Species of Pacific Northwest ArcynoPteryx (Females and,
in part, nymphs)
Key to the Subgenera and Species of Pacific Northwest Isogenus (Males and, in
part, females)
Subfamily Isoperlinae
Key to the Species of Pacific Northwest Isoperla (Males)
Key to the Species of Pacific Northwest Isoperla (Females)
Subfamily Perlodinae
Family Chloroperlidae
Subfamily Paraperlinae
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Table of Contents(Continued)
Page
Subfamily Chloroperlinae
Key to the Subgenera and Species of Pacific Northwest Alloperla (Males)
Key to the Subgenera and Species of Pacific Northwest Alloperla (Females)
Family Perlidae
Subfamily Acroneurinae
Key to the Subgenera and Species of Pacific Northwest Acroneuria (Males)
Key to the Subgenera and Species of Pacific Northwest Acroneuria (Females)
Key to the Subgenera and Species of Pacific Northwest Acroneuria (Nymphs)
Selected Bibliography
78
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90
List of Illustrations
Page
Figure
1
Adult of Brachyptera pacifica
2 Plecoptera
3
3
eggs
6
Dorsal view of constructed stonefly nymph
4 Ventral view of nymphal labium
5
6
7
8
9
10
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12
13
14
15
16
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32
33
Hind legs
Wings of stoneflies
Terminalia and nymphal sternites of Peltoperla
Male terminalia of Nemoura, in dorsal view
Male terminalia of Nemoura
Male terminalia of Nemoura
Female terminalia of Nemoura
Terminalia of Leuctra
Megaleuctra and Perlomyia
Male terminalia of Capnia, in lateral view
Male terminalia of Capnia, in lateral view
Male terminalia of Capnia, in lateral view and wing of Capnia venosa
Terminalia of Eucapnopsis
Terminalia of Isocapnia
Male terminalia of Brachyptera and Taeniopteryx
Terminalia of Pteronarcys and Pteronarcella
Diagrams of perlodid mesosternal ridge patterns
Terminalia of Arcynopteryx
Terminalia of Arcynopteryx
Head of Isogenus sorptus and terminalia of Isogenus
Wings of Isoperla marmorat a and terminalia of Calliperla and Isoperla
Wings of Isoperla phalerata and terminalia of Isoperla
Terminalia of Isoperla and Rickera
Terminalia of Diura knowltoni
Terminalia of Paraperlinae
Male terminalia of Alloperla
Head of Alloperla pintada and male terminalia of Alloperla
Female terminalia of Alloperla and male terminalia of Hastaperla chilnualna
Terminalia of Acroneuria and Claassenia
iv
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The Stoneflies (Plecoptera)
of the Pacific Northwest
Introduction
Stoneflies constitute one of the smaller insect orders, the nymphs of
which are strictly aquatic. Since the nymphs require cool water and an abundance of dissolved oxygen, adults are usually found near streams. In some
northern and alpine regions nymphs develop in lakes where the shore area is
composed of gravel. Wind action keeps the water well saturated with oxygen.
The world fauna of the order includes about 1,200 species, nearly 400 of
which occur in North America. One hundred forty-six species are known to
occur within the area covered by this treatmentWashington, Oregon, Idaho,
and British Columbia.
The principal importance of stoneflies from man's standpoint lies in
their value as food for fish, especially for stream-inhabiting trout (Dimick
and Mote, 1934). They serve as models for artificial angling lures and are
successfully employed for bait, as on the Deschutes River in Oregon where
two large species (Pteronarcys californica and Acroneuria pacifica) are used
to catch rainbow trout. Recently, stonefliesalong with other kinds of aquatic
insectshave been used as index organisms in pollution studies as was done
by U.S. Public Health Service personnel in Ohio (Gaufin and Tarzwell,
1952). Damage to the buds of soft fruits is attributed to members of one
genus, Brachyptera (Newcomer, 1918), but reports of crop damage by these
insects occur infrequently.
This treatment of stoneflies has been prepared as a guide to a general
knowledge of the order and is designed for use by the amateur as well as by
those with more advanced entomological training. It is assumed that anyone
attempting to identify stoneflies to genera and species possesses some knowledge of insect anatomy and entomological terminology.
Descriptions and records of many Pacific Northwest stoneflies are included in the Needham and Claassen monograph (1925). Since publication of
that basic work, large numbers of stoneflies have been collected from the
region. The late Dr. T. H. Frison of the Illinois Natural History Survey
identified large numbers of these insects, described a number of new species,
and published taxonomic and distributional notes on others (1935b, 1936,
1937, 1942a, 1942b). Duplicates of most species determined by Frison are
deposited in the collection at Oregon State College. Dr. Wm. E. Ricker of
the Fisheries Research Board of Canada has done a great deal of original
work on stoneflies, particularly western species, and has completed some of
the work started by Dr. Frison (Ricker 1943, 1952). Papers by other workers, Claassen (1937a, 1937b), Hanson (1942, 1943), Hoppe (1938), and
Jewett (1954a, 1954b, 1955) deal in whole or in part with stonefly material
1
2
STONEFLIES OF THE PACIFIC NORTHWEST
from the Pacific Northwest. Claassen's monograph of stonefly nymphs
(1931) includes a number of species found in the region.
The writer wishes to express his appreciation to Professor R. E. Dimick, head, Fish and Game Management Department, Oregon State College,
for initially stimulating his interest in the Plecoptera during his freshman
college days ; to Drs. Don C. Mote and H. A. Scullen, professors emeriti, Entomology Department, Oregon State College, for the privilege of studying
the stonefly collection which was long under their care, and for numerous
other courtesies ; to Dr. Paul Ritcher, present head, Entomology Department, Oregon State College, for his interest and guidance in the preparation
of this paper ; to Dr. Melville H. Hatch, Zoology Department, University of
Washington, for the privilege of studying the sizeable stonefly collection accumulated principally by Gertrude Hoppe and now under his care; to Dr.
M. T. James, Entomology Department, Washington State College, for allowing an examination and study of the Plecoptera material in his department's collection ; to Dr. W. F. Barr for the privilege of studying the stoneflies in the collection of the University of Idaho. To several friends, not associated with institutions, who have contributed numerous specimens to the
writer, grateful appreciation is extended ; substantial collections have been
contributed by James A. Baker, Kenneth M. Fender, John E. Davis, Borys
Malkin, and Wm. Markham Morton. Special appreciation is due Dr. Wm. E.
Ricker of the Fisheries Research Board of Canada for his generous assistance
and encouragement in the writer's stonefly work.
Life History
THE ADULT (Figure 1)
The adult stonefly is readily distinguished from other insects with which
it might be confused (such as male Embioptera and some Neuroptera), by
its relatively primitive venation and mouthparts, and by the fact that stoneflies always have three tarsal segments and two or three ocelli. The wings lie
flat on the body or over the sides, and most species have a pair of cerci extending from the tip of the abdomen. In size, stoneflies vary in body length
from 4 to 5 mm. (small Capnia and Nemoura) to 40 or 50 mm. (large Pteronarcys). Most stoneflies are normally winged, but a number are known to
be brachypterous. One little-known species, recorded only from New Mexico,
is apparently wingless in the male (Capnia fibula Claassen).
In order to gain a general understanding of the life history of stoneflies,
it is first necessary to recognize that the order comprises two suborders differing both morphologically and in details of their biology. Members of the two
suborders can be readily separated as either adults or nymphs by examination
of the labium, Figure 4. The Filipalpia have glossae and paraglossae of approximately the same length. In the Setipalpia, the paraglossae greatly exceed
the glossae. The Filipalpia are generally small to medium sized insects ; the
adults are diurnal ; many emerge as adults in the winter season ; and gen-
STONEFLIES OF THE PACIFIC NORTHWEST
3
Figure 1. Adult of Brachyptera pacifica. a, adult; b. mandibles; c, ventral terminalia of female; d, labium; e, maxilla; f, labrum, dorsally and ventrally (Newcomer, 1918).
erally the nymphs are vegetarians. The Setipalpia contain both small and large
sized species; adults are usually diurnal but many are crepuscular or nocturnal; they do not emerge in the winter season; and generally the nymphs
are carnivores. The adults of many species of Filipalpia are known to feed on
algae and plant foliage. It is probable most species must feed to oviposit suc-
cessfully. Setipalpia generally do not feed as adults, though some North
American species of Isoperla are known to do so.
In temperate regions there is a marked seasonal succession of species.
This is demonstrated in the accompanying chart for northwestern Oregon
for collecting sites of similar elevation and climate. Only species for which
considerable data are available are included in the chart. Insufficient data are
available to show graphically the relative abundance of each species on a time
scale, though it may be mentioned there is a period, usually of a week or so,
when each species is most abundant at a given locality. Although emergence
periods of many species overlap, the timing of their maximum abundance
differs. Species emerging in winter apparently live longer than species emerg-
ing during the summer, perhaps for a fortnight as compared to a few days.
Most stoneflies mate during daylight, but some Setipalpia, being nocturnal, mate only at night. In some species, mating is preceded by a courtship
SEASONAL DISTRIBUTION
The 44 species of stoneflies charted here occur in western Oregon. Additional species occur in the region but are omitted
because of inadequate data.
Species
Sept.
Oct.
Leuctra glabra
Nemoura californica
Alloperla autumna
Nemoura bifurcata
Capnia projecta
Capnia promota
Capnia excavata
Capnia melia
Nemoura cinctipes
Capnia columbiana
Taeniopteryx maura
Capnia tumida
Nemoura oregonensis
Brachyptera oregonensis
Leuctra occidentalis
Capnia jewetti
Nemoura dinticki
Nemoura obscura
Arcynopteryx curvata
Nov.
Dec.
Jan.
Feb.
Mar.
Apr.
May
June J
July
Aug.
Arcynopteryx parallela
Eucapnopsis brevicauda
Isocapnia grandis
Leuctra sara
Perlomyia collaris
Brachyptera nigripennis
Nemoura foersteri
Isoperla pinta
Pteronarcys princeps
Kathroperla perdita
Pteronarcys californica
Acroneuria pacifica
Isoperla fulva
Paraperla frontalis
Alloperla oregonensis
Alloperla coloradensis
Alloperla borealis
Pteronarcella regularis
Nemoura perplexa
A croneuria californica
Peltoperla brevis
Alloperla fidelis
Alloperla pacifica
Isogenus nonus
Alloperla pallidula
6
STONEFLIES OF THE PACIFIC NORTHWEST
pattern including drumming by the male. Prior to and following copulation,
males of some species strike their abdomens on the substrate. This frequently
produces sound. Stoneflies do not mate in flight. During copulation the male
rests on the female in supposition. Mating may occur several times, but once
is probably sufficient since sperm is stored in the female spermatheca (Brinck
1949, p. 119). Males of some species of Setipalpia await the emergence of
females from the nymphal skin, and copulation is immediately undertaken
even before the female exoskeleton has hardened.
Deposition of eggs may occur in flight or after the female crawls into
the water. Short-winged females invariably crawl into the water as do some
of the large species of Setipalpia and some of the small winter species of
Filipalpia. The extruded eggs of the female form a ball on the underside of
the tip of the abdomen which turns up so it appears that the egg mass is on
the dorsal tip of the abdomen. The number of eggs in a mass varies considerably, comprising only a few hundred in large species to over 1,400 in at least
one rather small winter species (Frison 1935, p. 299, Brinck 1949, p. 121).
Deposition of eggs in flight usually is accomplished by touching the surface
of the water with the tip of the abdomen, but there is evidence that egg masses
are actually released by some species above the water surface. The masses
disintegrate quickly when submerged.
THE EGG (Figure 2)
Eggs of stoneflies vary considerably in size and shape. Two general
types occur corresponding to the two suborders. The filipalpian egg is round
or slightly ovoid without an anchor plate. Adhesion to the substrate occurs
when a gelatinous outer membrane absorbs water and becomes sticky. The
shape of the setipalpian egg is variable but never round. It has an anchor
plate which adheres to the substrate.
The incubation period of a number of European stoneflies has been determined by Brinck (1949, pp. 128-130). Egg development takes place within
the abdomen of at least one Swedish species of Capnia, and hatching occurs
very quickly when eggs are deposited in water. In many species, two or three
weeks pass before deposited eggs hatch. In some of the larger setipalpian
species, two to three months are apparently required.
b
Figure 2. Plecoptera eggs. a, Pteronarcys dorsata; b, Isogenus frontalis colubrinus. (Needham and Claassen, 1925).
STONEFLIES OF THE PACIFIC NORTHWEST
7
THE NYMPH (Figure 3)
All stonefly nymphs upon hatching, and in the second instar, are extremely similar though the differences in mouthparts between the two suborders are always readily apparent. Nymphs of stoneflies have two long cerci
_maxillary palpus
labrum
antenna - - - -
___
epicranial arm
median ocellus
lateral ocellus
epicranial stem
marginal
transverse
occipital
groove - - marginal
flange
---
ridge
dorsal suture
thoracic gill _ _
wing pad
,
4
,
\,
`
'
t
irr,:231nrsddt
anal gill -
segment
segment
- - tarsus
cercus
Figure 3. Dorsal view of constructed stonefly nymph (Frison, 1935a).
8
STONEFLIES OF THE PACIFIC NORTHWEST
and a pair of claws on each foot. (Some mayflies have two cerci, but the feet
have only a single claw.) While nymphal development of most stonefly species
occurs in a year or less, some species require two and three years to complete
nymphal growth. A remarkable feature of stonefly nymphs is that many species pass through a resting period in the second instar when growth ceases.
Thus a large number of species are able to survive periods unfavorable to
growth such as very warm summer periods or very cold winter periods. The
sex of nymphs can usually be ascertained. In females there is usually a break
in the row of setae along the hind margin of the eighth sternite where the
subgenital plate will develop. The number of instars for North American
species studied ranges from 22 to 33 (Claassen 1931, pp. 7-8).
Second only to an adequate food supply, temperature is the principal fac-
tor governing growth and development of stonefly nymphs. The optimum
temperature range seems to be 5° to 12° C., at least in Sweden (Brinck 1949,
p. 136). In most streams, individual nymphs of a species grow at about the
same rate, but growth period and growth rate in different species vary ; consequently, there is a seasonal succession in the emergence of the species occurring in a stream. In springs of constant or nearly constant temperature,
growth and emergence are not so markedly seasonal, and adults may appear
over a period of many months. The biology and growth of a number of Swedish species have been carefully studied and recorded by Brinck (1949, pp.
130-140).
Of major importance from a taxonomic standpoint are external gills or
a lack of them in nymphs. Such gills occur on the mentum, submentum, neck,
thoracic segments, the first few abdominal segments, or extruded from the
anus. Since remnants of nymphal gills are present on adults for those species
which have them, these are of much importance in classifying the order.
Stonefly nymphs have differing feeding habits, some being exclusively
herbivores or carnivores while others are omnivorous. In general, Filipalpia
are herbivores, Setipalpia carnivores, though some species of the latter
group are known to be herbivores. Food habits of North American species
have not been studied extensively, but food and feeding habits of many European species have been studied in detail by Hynes (1941) and Brinck (1949,
pp. 154-165). Differences in feeding habits are reflected in head shape and
morphology of mouthparts. As a general rule, the setipalpian head is flatter
and mandibles heavier and longer than those in filipalpian species.
Distribution
In general the stonefly fauna of the western cordilleran region is of
similar aspect though there are some species of limited known range. Of the
79 species of stoneflies recorded by Ricker (1943) from southwestern British Columbia, 66 are known to occur in Oregon and 43 are found in California. Of 26 species recorded for western Montana (Castle, 1939), 19 are recorded as occurring in Washington. As further collecting is done in western
North America, indications of an even greater homogeneity in the Plecop-
STONEFLIES OF THE PACIFIC NORTHWEST
9
teran fauna can be expected than the above records indicate. Existing collection records nevertheless clearly demonstrate that many species have a limited range and distinctive differences occur in the stonefly fauna of the Rocky
Mountains, the Coast and Cascade Mountains, and the Sierra Nevada. Several northern species are holarctic, but none of these has been recorded in the
Pacific Northwest. One, Arcynopteryx cornpacta Mac Lachlan, may eventually
be found in the lakes of British Columbia and northern Washington. Several
stoneflies are widespread in North America : for example, Taeniopteryx
maura (Pictet) and Leuctra sara Claassen occur on the Pacific Coast as well
as in eastern North America.
The first prerequisite for stonefly nymphs is a habitat with cool, well
oxygenated water. They are therefore essentially stream inhabitants though
some species frequent lakes in northern and alpine areas. Most species occur
where the substrate is composed of gravel, but some are found in areas where
the bottom is covered with detritus. It therefore follows that some species
most commonly occur in rather sluggish streams, others in streams of considerable velocity. Water temperature is an important factor in the distribution of stoneflies since prolonged periods of water temperature in excess of
12° C. are highly inimical to most members of this group of aquatic insects.
For this reason, streams with prevailing cool spring and summer water
temperatures usually have a much richer stonefly fauna than those where
water temperatures become warm early in the season. The various species
are affected by the foregoing factors to varying degrees, and there are, of
course, many other elements in the environment to influence their distribution. For an excellent treatment of the ecology of stoneflies, reference is made
to Brinck's (1949, pp. 115-233) account of the Swedish species.
Specific environmental requirements of stoneflies are reflected in the
types of streams where they occur, some frequenting small creeks, some large
rivers, others both. Ricker (1943, pp. 12-15) has presented an interesting ac-
count of the populations of stoneflies of several types of streams in southwestern British Columbia. Several pairs of closely related species of Pacific
Northwestern stoneflies frequent different kinds of streams. For example,
Arcynopteryx parallels (Frison) occurs in large streams of relatively warm
water temperature such as the Willamette and Columbia Rivers and Arcynopteryx curvata Hanson frequents the smaller, colder tributary streams.
Pteronarcys californica Newport occurs in large rivers ; Pteronarcys princeps Banks, the smaller, colder streams. Much interesting work could be done
studying the ecological distribution of stoneflies in the Pacific Northwest.
The results could be of practical application in fishery management and pollution studies.
Preservation and Collection
Stonefly nymphs and adults should be preserved in 70 to 75 percent ethyl
or isopropyl alcohol and preferably placed in this liquid as they are collected.
Another preserving fluid suggested by Hardin and Mickel (1952, p. 6) is
modified Hood's solution (which has some advantages over alcohol), but
STONEFLIES OF THE PACIFIC NORTHWEST
10
specimens preserved in it are very soft and the solution is a nuisance to remove from instruments or fingers because of its stickiness. Stoneflies are
soft-bodied insects and, particularly during warm weather, will soon dry and
shrivel after death if left exposed to the air. A convenient vial for temporary
preservation is one of 3-dram capacity and measuring 65 by 17 mm., fitted
with a cork stopper. Avoid placing so many specimens in a vial that they are
improperly preserved. Specimens in vials of somewhat smaller diameter with
cotton plugs are best stored permanently in large jars filled with 70 percent
alcohol.
Adult stoneflies may be collected in several ways. From late autumn to
early spring, when most Capniids and many Nemourids emerge, concrete
bridges over streams are an excellent source of specimens which can be collected simply by employing a pair of forceps. During the remainder of the
year the most productive method of collecting is by sweeping vegetation along
streams with an insect net. Foliage of conifers is a favorite resting place for
many stoneflies where such trees border streams. Nocturnal species may be
taken at artificial lights, from under large stones bordering streams, and par-
ticularly from under loose bark of logs extending into the water. Cast
nymphal skins found on rocks, tree trunks, etc. near the water should be
preserved.
Nymphs are easily collected by overturning rocks and stirring gravel
in stream beds upstream from the opening of an aquatic net or fine-meshed
sieve. An excellent source of nymphs is among the debris which collects
at grills at water diversion structures. Nymphs may be reared by placing
them in small wire mesh cages fixed to a floating raft in streams in such a
manner that the upper portion of each cage is above the water level (Frison,
1935a, pp. 305-307).
Systematic Treatment
The taxonomic and distributional knowledge of the known stonefly fauna
of Oregon, Washington, Idaho, and British Columbia is summarized. Specific references for most of the genera and species may be found in Claassen's
catalog (1940) or in the Hanson and Aubert supplement to it (1952). Ricker's
recent extensive systematic paper (1952) includes treatment of the Nemouridae and Perlodidae and contains descriptions of many new subgenera and
species in these two families. The paper also includes revisions and descriptions in other groups. The systematic arrangement of Ricker (1950, 1952)
has been followed closely.
Master keys to the families and genera follow the list and should be
used first in placing unknown specimens. Keys to genera and species follow
very brief notes on families and subfamilies throughout the text, and these,
in conjunction with the figures of genitalia, should enable one to place most
specimens to species. A few extralimital species which may eventually be
found in the region are included in the keys. The known distribution of these
is noted parenthetically. Keys for the most part have been constructed by
STONEFLIES OF THE PACIFIC NORTHWEST
11
modifying keys found in Claassen (1931), Frison (1935, 1942), Needham
and Claassen (1925), and Ricker (1943, 1952).
In the treatment of each species, reference is made to the original description, a citation to the reference in the Needham and Claassen monograph (1925) if included in that work, and subsequent taxonomic references.
Papers devoted to distributional records are omitted unless they also include
taxonomic treatment, and references other than the original description are
omitted for the period prior to 1925 since most of these are contained in the
Needham and Claassen monograph. Brief notes are included to indicate gener-
ally the type of stream each species frequents, the seasonal occurrence of
adults, and the relative abundance. These notes should be used only as a general guide. Illustrations have been reproduced from published figures.
List of the Stoneflies of the Pacific Northwest
(Names in parentheses are synonyms ; those listed
without a number are of uncertain status.)
Suborder FILIPALPIA
I. Family PELTOPERLIDAE
A. Genus Peltoperla Needham 1905
Subgenus Soliperld Ricker 1952
1. campanula Jewett 1954
2. fenderi Jewett 1955
3. quadrispinula Jewett 1954
Subgenus Y oraperla Ricker 1952
4. brevis Banks 1907
5. mariana Ricker 1943
II. Family NEMOURIDAE
Subfamily NEMOURINAE
B. Genus Nemoura Pictet 1841
Subgenus Malenka Ricker 1952
6. bifurcate Claassen 1923
7. californica Claassen 1923
(lobata Frison 1936)
8. cornuta Claassen 1923
9. depressa Banks 1898
10. flexura Claassen 1923
11. perplexa Frison 1936
12. tiny Ricker 1952
Subgenus Ostrocerca Ricker 1952
13. dimicki Frison 1936
14. foersteri Ricker 1943
Subgenus Podmosta Ricker 1952
15. decepta Frison 1942
(rossi Ricker 1952)
12
STONEFLIES OF THE PACIFIC NORTHWEST
16. delicatula Claassen 1923
17. obscura Frison 1936
Subgenus Prostoia Ricker 1952
18. besametsa Ricker 1952
Subgenus Soyedina Ricker 1952
19. nevadensis interrupta Claassen 1923
20. producta Claassen 1923
(tuberculate Frison 1937)
Subgenus Visoka Ricker 1952
21. cataractae Neave 1933
Subgenus Zapada Ricker 1952
22. cinctipes Banks 1897
23. columbiana Claassen 1923
24. frigida Claassen 1923
25. haysi Ricker 1952
26. oregonensis Claassen 1923
27. wahkeena Jewett 1954
Subfamily LEUCTRINAE
C. Genus Leuctra Stephens 1835
Subgenus Despaxia Ricker 1943
28. augusta Banks 1907
(glabra Claassen 1923)
Subgenus Moselia Ricker 1923
29. infuscata Claassen 1923
Subgenus Paraleuctra Hanson 1941
30. forcipata Frison 1937
31. occidentalis Banks 1907
(bradleyi Claassen 1923; projecta Frison 1942)
32. purcellana Neave 1934
(bilobata Claassen 1937)
33. sara Claassen 1937
D. Genus Megaleuctra Neave 1934
34. complicata Claassen 1937
35. kincaidi Frison 1942
spectabilis Neave 1934
E. Genus Perlomyia Banks 1906
36. collaris Banks 1906
(solitaria and sobrina Frison 1936)
37. utahensis Needham and Claassen 1925
Subfamily CAPNIINAE
F. Genus Capnia Pictet 1841
38. columbiana Claassen 1924
39. confusa Claassen 1936
(nivalis Neave 1929)
40. cygna Jewett 1954
STONEFLIES OF THE PACIFIC NORTHWEST
41. elevata Frison 1942
42. elongata Claassen 1924
43. erecta Jewett 1955
44. excavata Claassen 1924
45. glabra Claassen 1924
46. gracilaria Claassen 1924
47. jewetti Frison 1942
48. licina Jewett 1954
49. lineata Hanson 1943
50. melia Frison 1942
51. nana Claassen 1924
52. oenone Neave 1929
53. oregona Frison 1942
54. petila Jewett 1954
55. porrecta Jewett 1954
56. projecta Frison 1937
57. promota Frison 1937
58. sextuberculata Jewett 1954
59. tumida Claassen 1924
60. umpqua Frison 1942
61. venosa (Banks) 1900
62. willametta Jewett 1955
63. zukeli Hanson 1943
G. Genus Eucapnopsis Okamoto 1922
64. brevicauda (Claassen) 1924
65. vedderensis Ricker
H. Genus Isocapnia Banks 1938
66. abbreviata Frison 1942
67. agassizi Ricker 1943
68. grandis (Banks) 1908
(fumigata Claassen 1937 ; fumosa Banks 1938)
69. spenceri Ricker 1943
spenceri, var. thujae Ricker 1943
Subfamily TAENIOPTERYGINAE
I.
Genus Brachyptera Newport 1851
Subgenus Doddsia Needham and Claassen 1925
70. occidentalis (Banks) 1900
Subgenus Taenionema Banks 1905
71. nigripennis (Banks) 1918
72. oregonensis (Needham and Claassen) 1925
73. Pacifica (Banks) 1900
74. pallida (Banks) 1902
(banksii Needham and Claassen 1925; pallidura
Claassen 1936; kincaidi Hoppe 1938)
13
STONEFLIES OF THE PACIFIC NORTHWEST
14
J.
Genus Taeniopteryx Pictet 1841
75. maura (Pictet) 1842
(nivalis Fitch 1847)
III. Family PTERONARCIDAE
K. Genus Pteronarcella Banks 1900
76. regularis (Hagen) 1873
L. Genus Pteronarcys Newman 1838
77. calif ornica Newport 1851
78. princeps Banks 1907
Suborder SETIPALPIA
IV. Family PERLODIDAE
Subfamily ISOGENINAE
M. Genus Arcynopteryx Klapalek 1904
Subgenus Frisonia Ricker 1943
79. picticeps Hanson 1942
(walkeri Ricker 1943)
Subgenus Megarcys Klapalek 1912
80. irregularis (Banks) 1900
81. signata (Hagen) 1874
82. subtruncata (Hanson) 1942
83. watertoni Ricker 1952
84. yosemite (Needham and Claassen) 1925
Subgenus Setvena Ricker 1952
85. bradleyi (Smith) 1917
86. tibialis (Banks) 1914
Subgenus Skwala Ricker 1943
87. curvata Hanson 1942
88. parallela (Frison) 1936
Subgenus Perlinodes Needham and Claassen 1925
89. aurea Smith 1917
(vagans Smith 1917)
N. Genus Isogenus Newman 1833
90. sorptus (Needham and Claassen) 1925
Subgenus Chernokrilus Ricker 1952
91. misnomus (Claassen) 1936
(obscura Needham and Claassen 1925)
Subgenus Cultus Ricker 1952
92. aestivalis (Needham and Claassen) 1925
93. pilatus (Frison) 1942
94. tostonus Ricker 1952
Subgenus Isogenoides Klapalek 1912
95. frontalis colubrinus Hagen 1874
(titusi Banks 1918; incesta Banks 1920)
96. elongates Hagen 1874
STONEFLIES OF THE PACIFIC NORTHWEST
Subgenus Kogotus Ricker 1952
97. modestus (Banks) 1908
98. nonus (Needham and Claassen) 1925
Subgenus Osobenus Ricker 1952
99. yakimae (Hoppe) 1938
Subfamily ISOPERLINAE
0. Genus Calliper la Banks 1947
100. luctuosa (Banks) 1906
P. Genus Isoperla Banks 1906
101. ebria (Hagen) 1875
102. fulva Claassen 1937
(chrysannula and cascadensis Hoppe 1938)
103. fusca Needham and Claassen 1925
104. gravitans (Needham and Claassen) 1925
105. longiseta Banks 1906
106. marmorata (Needham and Claassen) 1925
107. mormona Banks 1920
(insipida Hoppe 1938)
108. patricia Frison 1942
109. petersoni (Needham and Christenson) 1927
(fontium Neave 1929)
110. phalerata (Smith) 1917
111. pinta Frison 1937
112. rainiera Jewett 1954
113. sordida (Banks) 1906
114. trictura (Hoppe) 1938
Q. Genus Rickera Jewett 1954
115. venusta Jewett 1954
Subfamily PERLODINAE
R. Genus Diura Billberg 1820
Subgenus Dolkrila Ricker 1952
116. knowltoni (Frison) 1937
V. Family CHLOROPERLIDAE
Subfamily PARAPERLINAE
S. Genus Kathroperla Banks 1920
117. perdita Banks 1920
T. Genus Paraperla Banks 1906
118. frontalis (Banks) 1902
U. Genus Utaperla Ricker 1952
119. so pladora Ricker 1952
Subfamily CHLOROPERLINAE
V. Genus Alloperla Banks 1906
Subgenus Alloperla Banks 1906
15
16
STONEFLIES OF THE PACIFIC NORTHWEST
120. delicata Frison 1935
121. medveda Ricker 1952
122. serrata Needham and Claassen 1925
123. severa (Hagen) 1861
(elevata Frison 1935 ; thalia Ricker 1952)
Subgenus Neaviperla Ricker 1943
124. f orcipata Neave 1929
Subgenus Suwallia Ricker 1943
125. autumna Hoppe 1938
126. lineosa Banks 1918
127. pallidula (Banks) 1904
(dubia Frison 1935)
Subgenus Sweltsa Ricker 1943
128. albertensis Needham and Claassen 1925
129. borealis (Banks) 1895
130. coloradensis (Banks) 1898
131. exquisita Frison 1935
132. fidelis Banks 1920
133. fraterna Frison 1935
134. lamba Needham and Claassen 1925
135. occidens Frison 1937
136. oregonensis Frison 1935
137. pacifica (Banks) 1895
138. revelstoki Jewett 1955
Subgenus Triznaka Ricker 1952
139. diversa Frison 1935
140. pintada Ricker 1952
W. Genus Hastaperla Ricker 1935
141. chilnualna Ricker 1952
VI. Family PERLIDAE
Subfamily ACRONEURINAE
X. Genus Acroneuria Pictet 1841
Subgenus Acroneuria Pictet 1841
142. depressa Needham and Claassen 1922
Subgenus Callineuria Ricker 1954
143. calif ornica (Banks) 1905
144. theodora Needham and Claassen 1922
Subgenus Hesperoperla Banks 1938
145. pacifica Banks 1900
(pumila Banks 1906; delta Claassen 1937;
obscura Banks 1938;
okanagan Ricker 1935)
Y. Genus Claassenia Wu 1934
146. sabulosa (Banks) 1900
(arctica Klapalek 1916; languida Needham and
Claassen 1925)
STONEFLIES OF THE PACIFIC NORTHWEST
17
Key to the Families and Genera of the Stoneflies of Pacific
Northwestern United States*
Adults
1.
Paraglossae and glossae of about equal length, figure 4a
Suborder FILIPALPIA
2
Paraglossae much longer than the glossae, figure 4b
Suborder SETIPALPIA
13
Figure 4. Ventral view of
nymphal labium. a, Taeniopteryx maura; b, Isoperla Patricia. (a, Frison, 1935; b,
Frison, 1942b).
2 (1). Abdomen without branched gills on the ventral side; anal area of the forewing without crossveins or with only 1 row of them
Abdominal segments 1 and 2 with branched gills on the ventral side; anal
area of the forewing with 2 or more full rows of crossveins
_PTERONARCIDAE
3
12
3 ( 2 ). Form cockroach-like; ocelli 2 ; at least 10 costal crossveins in forewing
PELTOPERLIDAE
Peltoperla
Form typical ; ocelli 3 ; less than 10 costal crossveins in the forewing except
in Isocapnia which may have 10 or more
NEMOURIDAE
4
4 ( 3 ). Second tarsal segment much shorter than the first, figure 5a
Second tarsal segment at least as long as the first, figure 5b
5
TAENIOPTERYGINAE
5 ( 4 ). Wings lying nearly flat when at rest ; 2d anal vein of forewing forked,
11
figure 6a; cerci of adult 1-segmented
NEMOURINAE
Nemoura
Wings either rolled around the body at rest or wings flat when at rest and
with 2d anal vein of the forewing simple; cerci either 1-segmented or with
more than 4 segments
6 ( 5 ). Wings flat with 1 or rarely 2 intercubital crossveins in the forewing, figures
6c,f,g ;
ments
2d anal vein of the forewing simple; cerci with at least 4 segCAPNIINAE
6
9
Figure 5. Hind legs. a,
Leuctra claasseni; b, Taeniopteryx maura (Frison, 1935).
* Ignore wing characters for short-winged forms with aberrant venation.
18
STONEFLIES OF THE PACIFIC NORTHWEST
Wings rolled around the body ; intercubital crossveins of the forewing us-
ually more than 5, figures 6b,d,e; 2d anal vein of the forewing forked;
LEUCTRINAE
7 ( 6 ). Either the forewing with veins Rs and M with a common origin on R, figure 6d, or anal area of hindwing with 6 long veins, figure 6e
Veins Rs and M in the forewing arising from R beyond the origin of M,
cerci 1-segmented
7
8
Leuctra
Megaleuctra
Perlomyia
figure 6b, and anal area of hindwing with less than 6 veins
8 ( 7 ). Anal area of hindwing with 6 long veins, figure 6e
Anal area of hindwing with 3 veins, figure 6d
d
a
e
f
C
9
Figure 6. Wings of stoneflies. Forewing. a, Nemoura besametsa; b, Leuctra
occidentalis; c, Capnia projecta; d, Perlomyia utahensis; e, Megaleuctra spectabilis; f, Eucapnopsis brevicauda; g, Isocapnia sp. (c, f, Frison, 1937; e, Neave,
1934; b, d, Needham and Claassen, 1925; a, g, Ricker, 1943).
STONEFLIES OF THE PACIFIC NORTHWEST
19
9 ( 6 ). R1 of forewing bent upward at its origin; 1st annal vein of forewing bent
abruptly caudad at its junction with cu-a and then curved outwardly again,
figure 6c
Capnia
R1 of forewing not bent upward at its origin; 1st anal vein of forewing
without abrupt bend at its junction with cu-a, figures 6f,g
10
k
1
Figure 6 (continued). Wings of stoneflies. Fore and hind wings. h, Isogenus
frontalis colubrinus; i, Acroneuria pacifica; j, Arcynopteryx aurea; k, Alloperla
borealis; 1, Kathroperla perdita. (h-1, Needham and Claassen, 1925).
20
STONEFLIES OF THE PACIFIC NORTHWEST
10 ( 9 ). Cerci with fewer than 11 segments ; 1 crossvein in costal area beyond the
Eucapnopsis
cord, figure 6f
Cerci with more than 11 segments ; 2 or more crossveins in costal area beIsocapnia
yond the cord, figure 6g
11 ( 4 ). Coxal scars present ; male cerci 1-segmented; female 9th sternite without a
Taeniopteryx
long projection
Coxal scars absent ; male cerci with at least 3 segments ; female 9th sternite
Brachyptera
with a long projection
Pteronarcella
12 (2 ) Ventral abdominal gills on segment 3
Pteronarcys
No ventral abdominal gills on segment 3
13 (1). Profusely branched gills at the lower angles of the thorax ; cubito-anal
crossvein of forewing usually either in the anal cell or distant from it by no
more than its own length, figure 6i
PERLIDAE
ACRONEURINAE
24
Branched gills absent from the thorax ; cubito-anal crossvein, if present,
usually distant from the anal cell by more than its own length, figures 6h,j,k,1
14
14 (13). Gills absent or simple gills present on submentum, thorax, or abdomen ;
fork of 2nd anal vein of the forewing included in the anal cell so that its
2 branches leave the cell separately, figure 6h,j
PERLODIDAE
15
External gills entirely lacking ; 2nd anal vein of the forewing not forked
or forked beyond the anal cell except in Kathroperla which has the fork at
the margin of the cell or included in it, figures 6k,1
CHLOROPERLIDAE
20
15 (14). Male 10th tergite completely cleft
ISOGENINAE (in part)
16
17
Male 10th tergite entire or at most slightly notched
16 (15). Wings with 4 to many crossveins beyond the cord, and these usually arranged in an irregular network, figure 6j ; 7th abdominal sternite of male
Arcynopteryx
without a lobe
Wings with no more than 2 crossveins beyond the cord, figure 6h ; 7th abIsogenus
dominal sternite of male with a lobe behind
17 (15). Subanal lobes of male either formed into hooks or little modified
ISOPERLINAE
18
Subanal lobes of male produced inward and backward, meeting along their
inner face, figure 28
Diura
PERLODINAE
18 (17). Subanal lobes of male not formed into hooks ; male 10th tergite slightly
notched dorsally
Subanal lobes of male formed into hooks ; male 10th tergite entire
19 (18). Lobe on 7th sternite of male
Lobe, if present, on 8th sternite of male
Calliperla
19
Rickera
Isoperla
20 (14). Eyes usually small and set far forward; anal veins with 5 to 7 branches
reaching to the margin of the wing
PARAPERLINAE
21
Eyes large and normally situated ; anal veins with 4 branches at most
CHLOROPERLINAE
23
Kathroperla
21 (20). Head longer than wide
22
Head about as wide as long
22 (21). Ocellar area dark ; at least 3 crossveins in costal area beyond the subcosta ;
Paraperla
posterior margin of the male 7th sternite not raised and hairy
Ocellar area light ; less than 3 crossveins in the costal area beyond the subcosta ; posterior margin of the male 7th sternite raised and hairy
Utaperla
STONEFLIES OF THE PACIFIC NORTHWEST
21
Hastaperla
23 (20). Anal area of hindwing absent
Alloperla
Anal area of hindwing present
24 (13). Male 10th tergite with hooks arising from the lateral angles, figure 33h,
Claassenia
subanal lobes normal
Male 10th tergite without prolongations; subanal lobes of male modified
Acroneuria
into hooks
Key to the Families and Genera of the Stoneflies of Pacific
Northwestern United States
Nymphs
1.
Paraglossae and glossae of about equal length, figure 4a
Suborder FILIPALPIA
2
Paraglossae much longer than the glossae, figure 4b
Suborder SETIPALPIA
13
2 ( 1 ). Abdomen without branched gills on the ventral side
Abdomen with branched gills on the ventral side of abdominal segments
PTERONARCIDAE
1 and 2
3
12
3 ( 2 ). Form cockroach-like; ocelli 2; thoracic sterna produced posteriorly into
thin plates overlapping the segment behind
PELTOPERLIDAE
Peltoperla
Form typical ; ocelli 3, thoracic sterna not produced
NEM OURIDAE
4 ( 3 ). Second tarsal segment much shorter than the first, figure 5a
Second tarsal segment at least as long as the first, figure 5b
TAENIOPTERYGINAE
5 ( 4 ). Stout body with hindwing pads strongly diverging from the axis of the
4
5
11
Nemoura
Cylindrical, elongate body with hindwing pads nearly parallel with the axis
6
of the body
6 ( 5 ). Abdominal segments 1 to 9 divided by a membranous fold laterally
body
CAPNIINAE
9
At most only the first 7 abdominal segments divided by a membranous
fold
LEUCTRINAE
7
8
7 ( 6 ). Segments 1 to 7 of the abdomen divided laterally by a membranous fold
Leuctra
Only the first 5 or 6 abdominal segments divided laterally
8 ( 7 ). Body covered by rather coarse, appressed pile, the individual hairs of which
are about as long as a middle abdominal segment ; galea exceeding laMegaleuctra
cinia
Body with extremely fine pile, appearing naked; galea not quite reaching
Perlomyia
the end of the lacinia
9 ( 6 ). Cerci without mesal and lateral fringes of long silky hairs and abdominal
Capnia
segments without bristles
Cerci with fringes of long silky hairs or abdominal segments with bristles.... 10
10 ( 9 ). Abdominal segments with a few slender bristles ; cerci without long silky
Eucapnopsis
hairs
Abdominal segments without bristles ; cerci with fringes of long silky hairs
Isocapnia
Taeniopteryx
(
4
).
A
single
gill
on
each
coxa
11
Brachyptera
No coxal gills
Pteronarcella
12 ( 2 ). Ventral abdominal gills on segment 3
Pteronarcys
No ventral abdominal gills on segment 3
STONEFLIES OF THE PACIFIC NORTHWEST
22
13 (1). Profusely branched gills at the lower angles of the thorax
PERLIDAE
ACRONEURINAE
23
Branched gills absent from the thorax
14
14 (13). Body usually pigmented in a distinct pattern; cerci usually at least as long
as the abdomen; pads of the hindwings in nearly mature nymphs set at an
angle so that their central axis diverges considerably from the axis of the
body ;
domen
gills absent or simple gills present on submentum, thorax, or ab-
PERLODIDAE
15
Body almost concolorous without a pattern; cerci not more than 4 as long
as the abdomen; pads of hindwing nearly parallel to the axis of the body
except in mature Kathroperla which has the head elongated behind the
eyes ; external gills entirely lacking
CHLOROPERLIDAE
20
15 (14). A striped or strongly checkered pattern on the abdomen
16
No striped or checkered pattern on the abdomen except in Isogenus yakimae
which has a diamond-shaped, yellow spot in the interocellar area
17
16 (15). Maxilla with one spine
ISOGENINAE (in part)
Rickera venusta
Maxilla with two spines
ISOPERLINAE (ISOGENINAE, in part)
(Nymph of Calliperla undescribed)
Isoperla and Isogenus yakimae
17 (15). Thoracic gills present or submental gills at least twice as long as wide
ISOGENINAE (in part)
18
Thoracic gills absent ; submental gills lacking or their length less than twice
their width
19
18 (16). Either thoracic gills present or submental gills at least twice as long as
their greatest width and the mesosternal ridge pattern lacks a median ridge
Arcynopteryx
Thoracic gills absent and either submental gills lacking or their length is
less than twice their width except in the subgenus Isogenoides where a
median ridge joins the transverse ridge to the fork of the Y in the mesosternal ridge pattern
Isogenus (in part)
(Nymphs of some subgenera undescribed)
19 (17). Maxilla with one or two spines in which the major spine is equal to more
than of the length of the lacinia
Isogenus (in part)
(Nymphs of some subgenera undescribed)
Maxilla with two spines, the major spine equal to
lacinia
PERLODINAE
of the length of the
20 (14). Eyes usually small and set far forward; body narrow and elongate
Diura
PARAPERLINAE
21
(Nymph of Utaperla undescribed)
Eyes large and normally situated; body less elongate
CHLOROPERLINAE
21 (20). Head longer than wide
Head about as wide as long
22
Kathroperla
Paraperla
22 (20). Inner margins of the hindwing pads almost straight; length of mature
nymphs, excluding cerci, 5-7 mm.
Hastaperla
Inner margin of the hindwing pads curved or notched ; length of mature
nymphs, excluding cerci, usually over 6 mm.
Alloperla
23 (13). With a complete occipital ridge on head composed of closely set spinules
Head without a complete occipital ridge
Claassenia
Acroneuria
STONEY-1.1E5' OF THE PACIFIC NORTHWEST
23
Suborder FILIPALPIA
Family PELTOPERLIDAE
The nymphs of this family have a roach-like appearance and are usually
common in smaller streams where the current is of moderate velocity and the
water remains quite cool at all seasons. The arrangement of external gills
offers a ready means of identifying the different subgenera of which two
occur in this region, and the shape of the ventral thoracic plates seems to
offer specific characters to supplement those of the genitalia.
Key to the Subgenera and Species of Pacific Northwest Peltoperla
Males (in part, females)
No cervical gills; one pair of gills each on the meso- and metathorax
2
(Subgenus Soliperla)
A pair of cervical gills present; gills on all thoracic segments
4
(Subgenus Yoraperla)
quadrispinula
2 ( 1 ). Aedeagus of male with four bristle-like processes
3
Aedeagus of male with numerous hairs and spinules
fenderi
3 ( 2 ). Aedeagus of male with a V-shaped tuft of long hairs
campanula
Aedeagus of male with two rows of short spinules
brevis
4 ( 1 ). Length to tip of w., : s, 9-11 mm. in male, 10-13 mm. in female
mariana
Length to tip of wings, 11 mm. in male, 14-15 mm. in female
1.
Key to the Subgenera and Species of Pacific Northwest Peltoperla
Nymphs
(quadrispinula and fenderi not described)
No cervical gills; one pair of gills each on the meso- and metathorax
campanula
(Subgenus Soliperla)
A pair of cervical gills present ; gills on all three thoracic segments
2
(Subgenus Yoraperla)
2 (1). Length of mature nymph about 5 mm., its metasternal plate excavated be1.
hind
brevis
Length of mature nymph about 9 mm., its metasternal plate not exca-
vated
mariana
Peltoperla (Soliperla) campanula Jewett (figure 7)
1954. Peltoperla (Soliperla) campanula Jewett, Pan-Pac. Ent. 30 (3) :167-169,
male, female, and nymph.
Geographic range: Type locality: Oxbow Springs, Hood River County, Oregon.
Cascade Mountains of Oregon. Creeks. May-July. Common.
Peltoperla (Soliperla) fenderi Jewett (figure 7)
1955. Peltoperla (Soliperla) fenderi Jewett, Wasmann. Jour. Biol. 13(1) :145-146,
male.
Geographic range: Type locality: Saint Andrews Creek, Rainier National Park,
Washington. Known only by the holotype. Creeks. July. Rare.
Peltoperla (Soliperla) quadrispinula Jewett (figure 7)
1954. Peltoperla (Soliperla) quadrispinula Jewett, Pan-Pac. Ent. 30(3) :169-170,
male and female.
STONEFLIES OF THE PACIFIC NORTHWEST
24
Geographic range: Type locality : Wrangle Gap Camp, Rogue River National Forest,
Jackson County, Oregon. Coast Range of Oregon and California. Creeks. Late
May-August. Rare.
Peltoperla (Yoraperla) brevis Banks (figure 7)
1907. Peltoperla brevis Banks, Can. Ent. 39:328.
1925. Peltoperla brevis, Needham and Claassen, Monog. Plecop.,
p. 171; male
and female; wings, p. 321, figure 1; male and female genitalia, p. 353, figures
11-13.
1943. Peltoperla brevis, Ricker, Stoneflies SW B.C., pp. 46-47; description and
figures of nymph.
a
b
Cr
e
h
Figure 7. Terminalia and nymphal sternites of Peltoperla. a, lateral view of
male terminalia of campanula; b, ventral view of female terminalia of campanula; c, underside of aedeagus of fenderi ; d, ventral view of male terminalia of
quadrispinula; c, dorsal view of male terminalia of brevis; f, ventral view of
same; g; ventral view of female terminalia of brevis; h, outline of nymphal
sterna of brevis; i, outline of nymphal sterna of mariana. (a, b, d, Jewett, 1954b;
c, Jewett, 1955; e. f, g, Needham and Claassen, 1925; h, i, Ricker, 1943).
STONEFLIES OF THE PACIFIC NORTHWEST
25
1952. Peltoperla brevis, Ricker, Syst. Studies Plecop., p. 157; placed in new subgenus Yoraperla.
Geographic range: Type locality: British Columbia. British Columbia to California.
Small and large streams. Late spring and summer. Abundant.
Peltoperla (Yoraperla) mariana Ricker (figure 7)
1943. Peltoperla mariana Ricker, Stoneflies SW B.C., pp. 47-48; description and
figures of male, female, and nymph.
1952. Peltoperla mariana Ricker, Syst. Studies Plecop., p. 157; placed in new subgenus Yoraperla.
Geographic range: Type locality: Little Liumchin Creek, 6 miles SE of Cultus Lake,
British Columbia. British Columbia to Oregon. Creeks. April-July. Common.
Discussion: This species may be differentiated from P. brevis principally on the
the basis of size. Where they occur together in streams in the Cascades, both
sexes are separable on this character.
Family NEMOURIDAE
Subfamily NEMOURINAE
The Pacific Northwest is rich in species of this subfamily. It is probable
additions will be made to the present known fauna when more intensive collecting has been undertaken. Nymphs of many of the species are unknown,
but placement at least to subgenera can be accomplished with those possessing
external gills. While most species of the genus Nemoura occur in small to
medium sized streams, some occur in large swift rivers where the bottom is
composed of gravel and where the water contains an abundance of oxygen.
Key to the Subgenera and Species of Pacific Northwest
Nemoura
Males
(Figures 8, 9, 10)
Cerci elongated and heavily sclerotized to the tip, on at least the outer surface; the tip sharp or with 2 or more processes
Cerci membranous or weakly sclerotized (except for a distinct mesobasal
process, often sclerotized, in some species of Malenka) ; the tip blunt, without spines or processes
2 ( 1 ). Supra-anal process simple, slender, subacute; subanal lobes broad, with a
long slender spine mesally ; gills 2-branched, inserted at the sides of the
1.
2
4
mentum; cerci partly sclerotized with a major hook and a minor cusp
(Subgenus Visoka)
cataractae
Supra-anal process complex, broad; subanal lobes elongated and heavily
sclerotized; gills absent ; cerci long and slender, sclerotized
(Subgenus Ostrocerca)
3
3 (2). Posterior margin of 10th tergite with two long blunt processes near the
middle
Posterior margin of the 10th tergite without processes
dimicki
foersteri
4 ( 1 ). Veins A1 and A2 of the forewing united a little before their outer end;
subanal lobes long, upcurved, and flattened in side view
(Subgenus Soyedina)
Veins A1 and AR separate at the tip; subanal lobes not as above
5
6
STONEFLIES OF THE PACIFIC NORTHWEST
26
producta
5 ( 4 ). Tergites 2, 3, and 4 with conspicuous processes
Tergites 2, 3, and 4 without processes
n. interrupta
6 ( 4 ). Cervical gills present
7
19
Cervical gills absent
7 ( 6 ). Gills unbranched except in cinctipes and wahkeena which have fewer than
6 branches ; subanal lobes typically large and rectangular with a slender
inner lobe
(Subgenus Zapada)
8
Gills branched with 6 or more branches ; subanal lobes divided almost to
the base into 2 parts, one or both of them spinulose
(Subgenus Malenka)
13
d
b
h
f
Figure 8. Male terminalia of Nemoura, in dorsal view. a, tina; b, bifurcata;
c, perplexa; d, californica; e, dimicki; f, cornuta; g, foersteri; h, depressa;
decepta. (c, e, i, Frison, 1936; b, d, f, h, Needham and Claassen, 1925; a, Ricker,
1952; g, Ricker, 1943).
STONEFLIES OF THE PACIFIC NORTHWEST
27
8 ( 7 ). Wings usually uniformly dark; gills 12-15 times as long as wide
frigida
Wings conspicuously banded or mostly clear ; gills less than 10 times as
long as wide
9
9 ( 8 ). Gills branched at least once
10
Gills simple
11
10 ( 9 ). Wings banded, long; subanal lobe single
cinctipes
Wings not banded, brachypterous; subanal lobe composed of 2 parts wahkeena
11 ( 9 ). Gills constricted at the base and one or more times (usually twice) beyond
the base
columbiana
Gills constricted at the base only once if at all (a slight subterminal constriction occasionally in haysi)
12
12 (11). Subanal lobes quadrangular, the inner terminal angle rather sharp without
any sclerotized knob on the inner membrane
oregonensis
Subanal lobes with the inner terminal angle obtuse and rounded so that the
lobe appears almost triangular, and bearing a sclerotized knob on the distal
lateral corner of the inner membrane
haysi
13 (7). Mesobasal lobe of the cercus sclerotized and sharply pointed appearing to
be a part of the 10th tergite
14
Mesobasal lobe of the cercus, usually membranous, rounded, distinct from
the 10th tergite
15
b
pAih oAr= tr
C
a
e
d
9
Figure 9. Male terminalia of Nemoura. a-c, dorsal view; d-h, lateral view. a,
obscura; b, delicatula; c, wahkeena; d, cinctipes; e, columbiana; f, frigida; g,
oregonensis; h, interrupta. (a, Frison, 1936; c, Jewett, 1954b; b, d-h, Needham
and Claassen, 1925).
28
STONEFLIES OF THE PACIFIC NORTHWEST
14 (13). Mesobasal lobe directed straight back; outer part of the subanal lobes narcornuta
row, twice constricted
Mesobasal lobe directed inward and backward; outer part of the subanal
lobes broad, not constricted, but with a notch on the mesal margin .... californica
16
15 (13). Tip of the subanal lobes deeply bilobed
17
Tip of the subanal lobes simple
16 (15). Terminal divisions of the subanal lobes blunt; tip of the 9th sternite trunbifurcata
cate or rounded, not knob-like
Terminal divisions of the subanal lobes slender and acute; tip of the 9th
tina
sternite a rounded knob
17 (15). Tip of the subanal lobes slender, at least slightly twisted; mesobasal lobe
18
of the cercus not as below
Tip of the subanal lobes blunt, not twisted; mesobasal lobe of the cercus
about twice as broad as the cercus proper and moderately sclerotized.... depressa
a
_i_---\ ,\
CERCUS
SUBANAL LOSE
SUPRA- NAL
PROCESS
d
Figure 10. Male terminalia of Nemoura. a, d, lateral view; b, dorsal view; c,
ventral view, a, besametsa; b, haysi; c, cataractae; d, producta. (d, Frison, 1937;
c, Neave, 1933; a, b, Ricker, 1952).
STONEFLIES OF THE PACIFIC NORTHWEST
29
18 (17). Tip of the subanal lobes markedly twisted; main lobe of the cercus of
normal size, completely membranous, sharply marked off from the basal
flexura
lobe
Tip of the subanal lobes only slightly twisted; main lobe of cercus en-
larged and sclerotized, though unpigmented, continuous with the basal lobe
Perp/exa
on the outside
( 6 ). Supra-anal process slender, completely recurved along the 10th and 9th
besametsa
(Subgenus Prostoia)
tergites ; wings banded
Supra-anal process rather short, thick, complex in structure, and only
(Subgenus Podmosta)
20
slightly bent forward; wings not banded
20 (19). Supra-anal process with sharp, curved, laterally-directed horns near the
19
dece pta
tip
Supra-anal process without such horns
21
21 (20). Wings apparently always with cross veins in the apical field behind the
obscura
costal space; all veins margined with brown
Wings without crossveins in the apical field except in the costal space;
veins not margined with brown except along or near the cord
delicatula
Key to the Subgenera and Species of Pacific Northwest
Nemoura
Females
(Figure 11)
1.
2
2
Gills present under the head or neck
15
Gills absent
( 1 ). One branched gill present on each side of the mentum; wings not banded;
cataractae
(Subgenus Visoka)
7th sternite moderately produced
Two gills present on each side of the neck, branched or simple; wings
usually banded, spotted, or completely infuscated, 7th sternite variable in
3
shape
3 ( 2 ). Gills simple filaments except in cinctipes and wahkeena which have less than
6 branches ; 7th sternite produced completely over the 8th which is very
(Subgenus Zapada)
weak and without a notch
Gills with 6 or more branches ; 7th sternite moderately or little produced,
4
not covering all the 8th; 8th sternite bearing a distinct terminal or sub-
9
(Subgenus Malenka)
terminal notch
frigida
4 ( 3 ). Wings uniformly dark ; gills 12-15 times as long as broad
Wings conspicuously banded or mostly clear ; gills less than 10 times as
5
long as broad
6
5 ( 4 ). Gills branched at least once
Gills simple
7
cinctipes
6 ( 5 ). Wings banded and of normal length
wahkeena
Wings clear and brachypterous
7 ( 6 ). Gills constricted at the base and one or more times, usually twice, beyond
columbiana
the base
Gills constricted only at the base if at all (a slight subterminal constriction
8
occasionally in haysi)
8
( 7 ). Produced part of the 7th sternite usually light in color and narrowly
rounded, almost semicircular
oregonensis
Produced part of the 7th sternite dark-colored, at least along the broadly
haysi
rounded or nearly straight hind margin
STONEFLIES OF THE PACIFIC NORTHWEST
30
9 ( 3 ). Seventh sternite produced and rounded, but lacking a nipple ; 8th sternite
greatly swollen, considerably produced, and of ten very irregular in shape at
either side of the notch
cornuta
Produced portion of the 7th sternite bearing a distinct nipple whose base
is of ten anterior to the hind margin of the sternite (best seen in side view
and sometimes obscure in depressa) ; 8th sternite not as above
10
a
Figure 11. Female terminalia of Nemoura, ventral view. a, californica; b, de-
cepta; c, dimicki; d, foersteri; e, besametsa; f, cataractae; g, depressa; h, obscura; i, wahkeena. c, h, Frison, 1936; i, Jewett, 1954b; g, Needham and Claassen, 1925; d, e, Ricker, 1943; b, Ricker, 1952).
STONEFLIES OF THE PACIFIC NORTHWEST
10
31
( 9 ). Median notch not completely bisecting 8th sternite
Median notch completely bisecting 8th sternite
11
12
11 (10). Nipple of the 7th sternite low, inconspicuous, often scarcely recognizable
depressa
Nipple of the 7th sternite erect, easily distinguishable in side view at least,
its base set somewhat anterior to the hind margin of the sternite
californica
12 (10). Eighth sternite swollen on either side of the notch
13
Eighth sternite not swollen
14
13 (12). Notch of the 8th sternite margined by light sclerotization, if at all
bifurcata
Notch of the 8th sternite margined by heavy sclerotization in its anterior
third
tina
14 (12). Notch of the 8th sternite long, equal to at least the full lateral length of
the sternite ; its posterior half V-shaped ; its anterior half parallel sided
and margined by a series of irregular transverse lines or grooves
flexura
Notch of the 8th sternite short, not as long as the lateral length of the
15
sternite, very narrow at the middle and V-shaped at either end
perplexa
( 1 ). Veins Al and A2 united near the margin of the wing ; 7th sternite produced
over the full length of the 8th
(Subgenus Soyedina)
16
Veins Ai and A, not united except occasionally in obscura; 7th sternite
not produced over the full length of the 8th
17
16 (15). Subgenital plate of the 7th sternite more broadly rounded
Subgenital plate less broadly rounded
nevadensis interrupta
producta
17 (15). Wings mostly dark with a clear band across the middle of the outer field
(Subgenus Prostoia)
besametsa
Wings entirely clear or with some veins darkened near the cord
18
18 (17). Eighth sternite with a narrow median sclerotized band contrasting sharply
with the unsclerotized field at either side
(Subgenus Podmosta)
19
Eighth sternite without any median stripe, usually uniformly sclerotized
(Subgenus Ostrocerca)
21
19 (18). Wings usually with cross veins in the apical field beyond the costal space ;
most veins margined with brown
obscura
Wings without crossveins in the apical field except in the costal space ;
veins not margined except along or near the cord
20
20 (19). Median sclerotized stripe of the 8th sternite 3 to 4 times as long as its
greatest breadth, of nearly uniform width throughout
delicatula
Median sclerotized stripe of the 8th sternite not more than twice as long
as its greatest breadth, sometimes rather obscure
decepta
21 (18). Eighth sternite triangularly produced, with a narrow median slit and a
median knob just anterior to the slit
dimicki
Eighth sternite very little produced, broadly excavated
foersteri
Nemoura (Malenka) bifurcata Claassen (figure 8)
1923. Nemoura bifurcata Claassen, Can. Ent. 55 :282 ; description of male.
1925. Nemoura bifurcata, Needham and Claassen, Monog. Plecop., p. 204; male
genitalia, p. 359, figures 18, 19, 20.
1952. Nemoura bifurcata, Ricker, Syst. Studies Plecop., p. 32; placed in new subgenus Malenka and female described.
Geographic range : Type locality : Holotype male without locality label. Western
Washington and Oregon. Small creeks, springs. Most of the year. Common.
Discussion : In addition to the characters in the key, it may be mentioned that N.
bifurcata occurs in the coastal area, N. tina Ricker in the Cascades. This
species is associated with N. perplexa Frison in western Oregon in the spring
of the year and with N. californica Claassen in the fall.
32
STONEFLIES OF THE PACIFIC NORTHWEST
Nemoura (Malenka) californica Claassen (figure 8)
1923. Nomura californica Claassen, Can. Ent. 55 :284 ; description of male and
female.
1925. Nomura californica, Needham and Claassen, Monog. Plecop., p. 207; male
female genitalia, p. 361, figures 16-19 (figure 19 is evidently N. dimicki).
1929. Nemoura californica, Neave, Contr. Can. Biol. N. S. 4, p. 162, figure 8;
description and figure of female.
1936. Nemoura lobata Frison, Ann. Ent. Soc. Amer. 29:260, male genitalia, pl. I,
figures 5-7.
1952. Nemoura californica, Ricker, Syst. Studies Plecop., p. 33; placed in new subgenus Malenka.
Geographic range: Type locality: Oakland Hills, Alameda County, California. Alberta and British Columbia to California and New Mexico. Creeks. Fall and
spring. Abundant in fall, rare in spring.
Nemoura (Malenka) cornuta Claassen (figure 8)
1923. Nemoura cornuta Claassen, Can. Ent. 55 :285 ; description of male.
1925. Nemoura cornuta, Needham and Claassen, Monog. Plecop., p. 207; male genitalia, p. 361, figures 13-15.
1943. Nemoura cornuta, Ricker, Stoneflies SW B. C., p. 62 ; female genitalia and
nymph, p. 60, figures 26-28.
1952. Nemoura cornuta, Ricker, Syst. Studies Plecop., p. 33; placed in new subgenus Malenka.
Geographic range : Type locality ; Nanaimo, British Columbia. Coast and Cascade
Mountains of British Columbia, Washington, and Oregon. Small creeks.
April-July. Abundant.
Nemoura (Malenka) depressa Banks (figures 8, 11)
1898. Nemoura depressa Banks, Trans. Amer. Ent. Soc. 25:200; description of
female.
1925. Nemoura depressa, Needham and Claassen, Monog. Plecop., p. 206; wing, p.
355, figure 6; male and female genitalia, p. 361, figures 9-12.
1952. Nemoura depressa, Ricker, Syst. Studies Plecop., p. 33 ; placed in new subgenus Malenka.
Geographic range : Type locality : Cottage Grove, Oregon. Oregon and northern
California; New Mexico. Creeks. April-June. Rare in Oregon.
Nemoura (Malenka) flexura Claassen
1923. Nemoura flexura Claassen, Can. Ent. 55:284, male.
1925. Nemoura flexura, Needham and Claassen, Monog. Plecop., p. 205; male and
female genitalia, p. 361, figures 5-8.
1952. Nemoura flexura, Ricker, Syst. Studies Plecop., p. 34, placed in new subgenus
Malenka.
Geographic range : Type locality : Boulder, Colorado. Eastern Oregon and Washington; Montana to Colorado. Small creeks. April-June. Common.
Nemoura (Malenka) perplexa Frison (figure 8)
1936. Nemoura perplexa Frison, Ann. Ent. Soc. Amer. 29:259; description of male
and female.
1952. Nemoura perplexa, Ricker, Syst. Studies Plecop., p. 34, placed in new subgenus Malenka.
Geographic range : Type locality : Swim, Oregon, summit of ranger station, Mt.
Hood National Forest. Western Oregon and Washington. Small creeks,
springs. Most of year. Common.
Discussion : This species occurs in the Coast and Cascade Ranges whereas the range
of N. flexura Claassen, principally a Rocky Mountain species, extends only
to eastern Oregon and Washington.
STONEFLIES OF THE PACIFIC NORTHWEST
33
Nemoura (Malenka) tina Ricker (figure 8)
1952. Nemoura (Malenka) tina Ricker, Syst. Studies Plecop., p. 35; male genitalia,
p. 34, figures 16-18.
1954. Nemoura (Malenka) tina, Jewett, Jour. Fish. Res. Bd. Can. 11(5) :543, female
genitalia.
Geographic range : Type locality: Iron Creek, Lewis County, Washington. Washington, Oregon, and Idaho. Creeks. May-July. Rare.
Nemoura (Ostrocerca) dimicki Frison (figures 8, 11)
1936. Nemoura dimicki Frison, Ann. Ent. Soc. Amer. 29:256, male, female, and
nymph; male genitalia, p. 264, figures 8-11; female genitalia, p. 265, figure 17.
1952. Nemoura dimicki, Ricker, Syst. Studies Plecop., p. 40; placed in new subgenus Ostrocerca.
Geographic range : Type locality: Branch of Dixon Creek, Corvallis, Oregon. Coast
and Cascade Mountain valleys from southern British Columbia to Oregon.
Creeks. February-May. Common.
Nemoura (Ostrocerca) foersteri Ricker (figures 8, 11)
1943. Nemoura foersteri Ricker, Stoneflies SW F.C., p. 70; male and female genitalia, figures 38-40, 42.
1952. Nemoura foersteri Ricker, Syst. Studies Plecop., p. 40; placed in new subgenus Ostrocerca.
Geographic range : Type locality: Reservoir Creek, Cultus Lake, British Columbia.
Coast and Cascade Mountain valleys from British Columbia to Oregon. Creeks.
March-May. Common.
Discussion: This species, like N. dimicki Frison, commonly occurs in small meander-
ing streams on the floor of the Willamette Valley and appears to be absent
from swift creeks at higher elevations.
Nemoura (Podmosta) decepta Frison (figures 8, 11)
1942. Nemoura decepta Frison, Pan-Pac. Ent. 18:13, male; male genitalia, figures
2a-2d.
1943. Nemoura decepta, Ricker, Stoneflies SW B.C., p. 69-70, male, female, and
nymph; male and female genitalia, nymph, p. 71, figures 34-37.
1952. Nemoura decepta, Ricker, Syst. Studies Plecop., p. 43; placed in new subgenus Podmosta.
1952. Nemoura rossi Ricker, ibid., p. 45, description and figure of female and placed
in new subgenus Podmosta.
1954. Nemoura (Podmosta) decepta, Ricker, Trans. Ent. Soc. B.C., 51:37; above
synonymy indicated.
Geographic range : Type locality: Estes Park, Colorado. Colorado; British Columbia
to Oregon. Creeks. May-July. Common.
Nemoura (Podmosta) delicatula Claassen (figure 9)
1923. Nemoura delicatula Claassen, Can. Ent. 55 :285 ; description of male and
female.
1925. Nemoura delicatula, Needham and Claassen, Monog. Plecop., p. 204; male and
female genitalia, p. 359, figures 14-17.
1952. Nemoura delicatula, Ricker, Syst. Studies Plecop., p. 43; placed in new subgenus Podmosta.
Geographic range : Type locality : Boulder, Colorado. Central British Columbia to
California and Colorado. Creeks. April-July. Common.
Nemoura (Podmosta) obscura Frison (figure 9)
1936. Nemoura obscura Frison, Ann. Ent. Soc. Amer. 29:258, male and female,
nymph; male and female genitalia, pp. 264-265, figures 1, 12-14, 15, 18.
34
.STONEFLIES OF THE PACIFIC NORTHWEST
1952. Nemoura obscura, Ricker, Syst. Studies Plecop., p. 45 ; placed in new subgenus Podmosta.
Geographic range : Type locality : Brooklane Creek, Corvallis, Oregon. Coast and
Cascade Mountain valleys of Washington and Oregon. Creeks. February-May.
Common.
Discussion : This species, unlike the two preceding ones in the subgenus Podnzosta,
occurs in meandering valley streams at low elevations.
Nemoura (Prostoia) besametsa Ricker (figures 10, 11)
1923. Nemoura glabra Claassen (misapplied to western specimens) Can. Ent. 55:281
(Not the holotype).
1943. Nemoura completa, Ricker, Stoneflies SW B.C., p. 68; male, female and nymph
(not Walker 1852).
1943. Nemoura species A Ricker, ibid., p. 72 ; wing and female genitalia, p. 71,
figures 41 and 43.
1952. Nemoura besametsa Ricker, Syst. Studies Plecop., p. 48; male genitalia, p. 44,
figure 20; placed in new subgenus Prostoia.
Geographic range: Type locality : Vedder Crossing, British Columbia. Southern
British Columbia to California and Colorado. Creeks, small rivers. April-June.
Common.
Nemoura (Soyedina) nevadensis interrupta Claassen (figure 9)
1923. Nemoura interrupta Claassen, Can. Ent. 55:288; description of male.
1925. Nemoura interrupta, Needham and Claassen, Monog. Plecop., p. 217; male
genitalia, p. 367, figures 16-18.
1942. Nemoura pseudoproducta Frison, Pan-Pac. Ent. 18 :11; male genitalia, p. 12,
figures la-lb.
1943. Nemoura interrupta, Ricker, Stoneflies SW B.C., p. 66; female genitalia, p.
67, figure 30.
1952. Nemoura nevadensis interrupta, Ricker, Syst. Studies Plecop., p. 52; placed
in new subgenus Soyedina and treated as a subspecies of N. nevadensis.
Geographic range : Type locality : Seattle, Washington. Coast and Cascade Mountains of British Columbia, Washington, and Oregon. Creeks. March-July.
Common.
Discussion : This species frequently occurs with N. producta. When taken together,
females of the two species are easily separated on the basis of the shape of the
subgenital plates, that of N. interrupta being more rounded and usually shorter
than N. producta. Where only females of one species are taken, absolute
reliance cannot be placed on the shape of the subgenital plate.
Nemoura (Soyedina) producta Claassen (figure 10)
1923. Nemoura producta Claassen, Can. Ent. 55 :286 ; description of male.
1925. Nemoura producta, Needham and Claassen, Monog. Plecop., p. 211; male and
female genitalia, p. 365, figures 1-4.
1937. Nemoura tuberculata Prison, Bull. Ill. Nat. Hist. Sur. 21:84, male and female
genitalia, figure 71.
1943. Nemoura producta, Ricker, Stoneflies SW B.C., pp. 65-67; female and nymph,
figures 29 and 31.
1952. Nemoura producta, Ricker, Syst. Studies Plecop., p. 52 ; placed in new subgenus Soyedina.
Geographic range : Type locality : Holotype, male, allotype, female, without any
label. Coast and Cascade Mountains from southern British Columbia to Oregon. Creeks. March-July. Common.
Nemoura (Visoka) cataractae Neave (figures 10, 11)
1933. Nemoura cataractae Neave, Can. Ent. 65:238, figures 3-4; description of male.
1943. Nemoura cataractae, Ricker, Stoneflies SW B.C., p. 58; female and nymph,
p. 60, figures 20-22.
STONEFLIES OF THE PACIFIC NORTHWEST
35
1952. Nemoura cataractae, Ricker, Syst. Studies Plecop., p. 54; placed in new subgenus Visoka.
Geographic range : Type locality : Lake O'Hara, British Columbia. Southern British
Columbia to Montana and California. Creeks. March-May. Common.
Nemoura (Zapada) cinctipes Banks (figure 9)
1897. Nemoura cinctipes Banks, Trans. Amer. Ent. Soc. 24:21.
1925. Nemoura cinctipes, Needham and Claassen, Monog. Plecop., p. 212 ; wings,
p. 355, figure 2; male and female genitalia, p. 365, figures 5-8.
1939. Nemoura cinctipes, Castle, Can. Ent. 71 :208-209 ; description and figure of
nymphal gills.
1952. Nemoura cinctipes, Ricker, Syst. Studies Plecop., p. 57; placed in new subgenus Zapada.
Geographic range : Type locality : Olympia, Washington. Alaska, British Columbia,
and Alberta south to Utah and California. Small and large streams. FebruaryJuly. Abundant.
Nemoura (Zapada) columbiana Claassen (figure 9)
1923. Nemoura columbiana Claassen, Can. Ent. 55:286; description of male.
1925. Nemoura columbiana, Needham and Claassen, Monog. Plecop., p. 203; male
genitalia, p. 359, figures 11-13.
1933. Nemoura columbiana, Neave, Can. Ent. 65:238, female; female genitalia, p.
236, figure 5.
1943. Nemoura columbiana, Ricker, Stoneflies SW B.C., p. 61, figure 24; nymph.
1952. Nemoura columbiana, Ricker, Syst. Studies Plecop., p. 57; placed in new subgenus Zapada.
Geographic range : Type locality: Laggan (Lake Louise), Alberta. Alaska and Alberta south to Utah and California. Creeks, small rivers. March-June. Common.
Nemoura (Zapada) frigida Claassen (figure 9)
1923. Nemoura frigida Claassen, Can. Ent. 55:285; description of male.
1925. Nemoura frigida, Needham and Claassen, Monog. Plecop., p. 202; male genitalia, p. 359, figures 5-7.
1943. Nemoura frigida, Ricker, Stoneflies SW B.C., pp. 59 -60; female and nymph,
figures 23 and 25.
1952. Nemoura frigida, Ricker, Syst. Studies Plecop., p. 57; placed in new subgenus Zapada.
Geographic range : Type locality: Sitka, Alaska. Alaska to California and Colorado.
Creeks, small rivers. March-June. Common.
Nemoura (Zapada) haysi Ricker (figure 10)
1952. Nemoura haysi Ricker, Syst. Studies Plecop., pp. 58-60; male and female
genitalia, figures 32-35; placed in new subgenus Zapada.
Geographic range : Type locality: Upper Gallatin River, 5 miles east of highway
number 191, Yellowstone National Park, Wyoming. Alaska south to Colorado
and California. Creeks, small rivers. April-July. Rare.
Discussion: This species is very difficult to distinguish from N. oregonensis. Generally, oregonensis has shorter, more tapered gills with a sharp constriction at
their base ; however, the gills can be misleading. The male subanal lobes of
haysi have a sharper angle mesally and the female subgenital plate is more
narrowly rounded and usually lighter in color than oregonensis. It seems to
be a widely distributed, though scarce, species.
Nemoura (Zapada) oregonensis Claassen (figure 9)
1923. Nemoura oregonensis Claassen, Can. Ent. 55:288; description of male.
1925. Nemoura oregonensis, Needham and Claassen, Monog. Plecop., p. 213, male ;
male genitalia, p. 365, figures 9-11.
36
STONEFLIES OF THE PACIFIC NORTHWEST
1937. Nemoura oregonensis, Frison, Bull. Ill. Nat. Hist. Sur. 21:83-84; female
genitalia, figure 70.
1943. Nemoura oregonensis, Ricker (in part), Stoneflies SW B.C., p. 62, nymph ;
nymph, p. 67, figure 31.
1952. Nemoura oregonensis, Ricker, Syst. Studies Plecop., pp. 60-61; placed in new
subgenus Zapada.
Geographic range : Type locality : Harney County, Oregon. Yukon and Alaska south
to Colorado and California. Creeks, small rivers. February-June. Abundant.
Nemoura (Zapada) wahkeena Jewett (figures 9, 11)
1954. Nemoura (Zapada) wahkeena Jewett, Pan-Pac. Ent. 30(3) :171-172, description and figures of male and female.
Geographic range : Type locality : Wahkeena Falls, Multnomah County, Oregon.
Known only from Wahkeena Falls. Creek. April. Rare.
Discussion : This small species is of special interest because both sexes are brachypterous. Adults have been found on small limbs of creek dogwood, on trunks
of alders, and in the curled tips of young fern fronds. It is probable that
the species has a more widespread distribution than present records indicate.
Subfamily LEUCTRINAE
Leuctra and Perlomyia are usually abundant in streams where they occur,
but Megaleuctra seems always to be a rarity. Because so few specimens of
the latter have been collected, specific characters have not been discovered to
distinguish the females of the two species described from males, and it is
conjectural whether M. spectabilis Neave, based on females, represents a third
western North American species.
Key to the Subgenera and Species of Pacific Northwest Leuctra
Males
(Figure 12)
No ventral lobe on the 9th sternite
(Subgenus Despaxia)
augusta
A ventral lobe present on the 9th sternite
2
2 ( 1 ). Cerci heavily sclerotized with terminal and lateral pointed projections ;
body color usually black
(Subgenus Paraleuctra)
3
Cerci large, membranous, or weakly sclerotized, without sharp angles, body
(Subgenus Moselia)
color brown
infuscata
3 (2). Titillator with a large membranous bulb at the tip ; the upper, longer prong
of the bifurcate cercus hooked
occidentalis
Titillator without a bulbous tip ; upper prong of cercus not hooked
4
4 ( 3 ). Wings brown ; upper portion of cercus with 3 protuberances or lobes
1.
5
purcellana
Wings blackish ; upper portion of cercus a single lobe sometimes with small
tooth on inner margin
5
( 4 ). Upper prong of cercus longer than the lower and with a small tooth on the
inner margin
sara
The two tips of the cercus widely separated forming a lower and an upper
portion which are of about equal size and shape; no tooth on inner margin
of upper prong
forcipata
STONEFLIES OF THE PACIFIC NORTHWEST
37
Key to the Subgenera and Species of Pacific Northwest Leuctra
Females
(Figure 12)
Abdomen sclerotized only in very small patches on the sides
augusta
(Subgenus Despaxia)
2
Abdomen normally wholly sclerotized on the sides and below
2 ( 1 ). Body color usually blackish; subgenital plate with lateral projections and a
3
(Subgenus Paraleuctra)
median notch
1.
Figure 12. Terminalia of Leuctra. a, b, d, e, lateral view of males; c, dorsal
view of male; f, g, h, ventral view of females. a, forcipata; b, h, augusta; c, g,
infuscata; d, sara; e, f, occidentalis. (a, Frison, 1937; b-g, Needham and Claassen, 1925; h, Ricker, 1943).
38
STONEFLIES OF THE PACIFIC NORTHWEST
Body color brown with a whitish stripe along the costal space of the f orewing ; subgenital plate with a median projection below and anterior to the
(Subgenus Moselia)
two lateral projections
infuscata
3 (2) Subgenital plate extending little beyond the 8th sternite
occidentalis
Subgenital plate extending about its own length beyond the 8th sternite
4
4 ( 3 ) Wings blackish; subgenital plate not terminating with a sharply set off
sara, forcipata
bilobed tip
Wings brown; subgenital plate with a strongly bilobed tip
purcellana
Key to the Subgenera and Species of Pacific Northwest Leuctra
Nymphs
(forcipata and purcellana not described)
1.
Body nearly naked (legs moderately hairy) ; first 5 abdominal segments
divided laterally by a fold ; femora of hind leg very large
(Subgenus Despaxia)
augusta
Body at least moderately hairy; first 6 abdominal segments divided laterally
2
by a fold; hind femora normal
2 ( 1 ). Body moderately hairy; longest dorsal abdominal hairs not near hind margin of each segment
(Subgenus Paraleuctra)
3
Body very hairy ; longest dorsal abdominal hairs near the hind margin of
(Subgenus Moselia)
infuscata
each segment
3 (2). Abdominal tergites with a band of unusually long hairs on either side,
about a third of the way from the anterior margin
Abdominal tergites with only 2 or 4 delicate hairs
occidentalis
sara
Leuctra (Despaxia) augusta Banks (figure 12).
1907. Leuctra augusta Banks, Can. Ent. 39 :330; description of female.
1923. Leuctra glabra Claassen, Can. Ent. 55 :261; description of male.
1925. Leuctra augusta, Needham and Claassen, Monog. Plecop., p. 224; female
genitalia, p. 375, figure 1.
1925. Leuctra glabra, Needham and Claassen, ibid., p. 228, male genitalia, p. 373,
figures 9-11.
1929. Leuctra glabra, Neave, Contr. Can. Biol. Fish. 4:162 ; description of female.
1943. Leuctra glabra, Ricker, Stoneflies SW B.C., pp. 79-80; description of male,
female, nymph, and placed in new subgenus Despaxia.
1954. Leuctra (Despaxia) augusta, Ricker, Proc. Ent. Soc. B.C., 51:37-38; above
synonymy indicated.
Geographic range: Type locality : Port Renfrew, British Columbia. Alaska and Alberta to California. Creeks. August-November. Common.
Discussion: As indicated above, the nomenclature of the species was confused until
Ricker in 1954 untangled the names applied to this species, to L. occidentalis
Banks, and to L. sara Claassen. L. glabra is a large species which emerges in
early autumn. In western Oregon it is associated with Nentoura californica and
Alloperla autumna.
Leuctra (Moselia) infuscata Claassen (figure 12).
1923. Leuctra infuscata Claassen, Can. Ent. 55:262 ; description of male and female.
1925. Leuctra infuscata, Needham and Claassen, Monog. Plecop., pp. 230-231; male
and female genitalia, p. 377, figures 3-5.
1943. Leuctra infuscata, Ricker, Stoneflies SW B.C., p. 81, nymph, p. 79, figure 50;
placed in new subgenus Moselia.
Geographic range: Type locality : Seattle, Washington. British Columbia to California. Creeks. April-July. Abundant.
STONEFLIES OF THE PACIFIC NORTHWEST
39
Leuctra (Paraleuctra) forcipata Frison (figure 12).
1937. Leuctra forcipata Frison, Bull. Ill. Nat. Hist. Sur. 23(3) :85, figure 72; description and figure of male and female.
Geographic range: Type locality : Corvallis, Oregon. Oregon and California. Creeks.
April-May. Rare.
Discussion: There is some question whether L. forcipata is actually a distinct species
or merely a variant of L. sara. Male specimens of sara from various western
localities show considerable variation in the shape of the claspers, but since
complete gradation in the shape of the claspers between sara and forcipata
has not been demonstrated two species are considered to be involved.
Leuctra (Paraleuctra) occidentalis Banks (figure 12).
1907. Leuctra occidentalis Banks (not Needham and Claassen, 1925), Can. Ent.
39:329 -330.
1923. Leuctra bradleyi Claassen, Can. Ent. 55:257; description of male.
1925. Leuctra bradleyi, Needham and Claassen, Monog. Plecop., pp. 225-226; wing,
p. 355, figure 1; male genitalia, p. 373, figures 12-15.
1943. Leuctra bradleyi, Ricker, Stoneflies SW B.C.,
p. 76,
female and nymph;
nymph, p. 79, figure 44; placed in Paraleuctra.
1954. Leuctra (Paraleuctra) occidentalis, Ricker, Proc. Ent. Soc. B.C., 51:38; above
synonymy indicated.
Geographic range: Type locality : Laggan (Lake Louise), Alberta. Alberta and
British Columbia south to Utah and California. Creeks and rivers. FebruaryMay. Common.
Leuctra (Paraleuctra) purcellana Neave (figure 12).
1934. Leuctra purcellana Neave, Can. Ent. 66:2, male.
1937. Leuctra bilobata Claassen, Jour. Kans. Ent. Soc. 10(2) :45, female.
1952. Leuctra (Paraleuctra) purcellana, Ricker, Syst. Studies Plecop., p. 172, above
synonymy indicated.
Geographic range: Type locality : Purcell Range, British Columbia. British Columbia. Creeks. June-August. Rare.
Leuctra (Paraleuctra) sara Claassen (figure 12).
1925. Leuctra occidentalis, Needham and Claassen, Monog. Plecop., p. 231, male and
female; male genitalia, p. 373, figures 6-8; female genitalia, p. 375, figure 12.
1937. Leuctra sara Claassen, Jour. Kans. Ent. Soc. 10(2) :44, figure 11; description
and figures of male and female.
1941. Leuctra sara, Hanson, Bull. Brooklyn Ent. Soc. 36(2) :64, description and
figures of nymph; placed in new genus Paraleuctra.
1955. Leuctra (Paraleuctra) sara, Ricker, Proc. Ent. Soc. B.C., 51:38; above
synonymy indicated.
Geographic range: Type locality: Ringold Lloyd Preserve, near Ithaca, New York.
Eastern United States ; British Columbia south to Colorado and California.
Creeks and rivers. March-July. Abundant.
Key to the Species of Pacific Northwest Megaleuctra
Males
(spectabilis undescribed)
(Figure 13)
Ninth tergite with a pair of inwardly directed, sharply-pointed tubercles on
kincaidi
the middle area
Ninth tergite with a pair of dorsally directed, bluntly pointed tubercles on
complicata
the middle area
40
STONEFLIES OF THE PACIFIC NORTHWEST
Megaleuctra complicata Claassen (figure 13).
1937. Megaleuctra complicata Claassen, Jour. Kans. Ent. Soc. 10:48-49, male; male
genitalia, p. 51, figure 15.
Geographic range: Type locality: Corvallis, Oregon. Oregon. Creeks. March-April.
Rare.
Megaleuctra kincaidi Frison (figure 13).
1942. Megaleuctra kincaidi Frison, Pan-Pac. Ent. 18: 15-16, male; wing and male
genitalia, p. 12, figures 4a-4d.
1954. Megaleuctra kincaidi, Jewett, Jour. Fish. Res. Bd. Can. 11(5) :543-545; description and figure of nymph.
Geographic range: Type locality : Fryingpan Creek, elevation 5,000 feet, Mount
Rainier National Park, Washington. Washington, Oregon, and Idaho. Creeks.
April-July. Rare.
a
e
Figure 13. a, Magaleuctra kincaidi; b, M. complicata; c, d, Perlomyia collaris;
e, P. utahensis. a, b, d, e, lateral view of male terminalia; c, ventral view of female terminalia. (b, Claassen, 1937b; c, d, Frison, 1936; a, Frison, 1942a; e, Needham and Claassen, 1925).
STONEFLIES OF THE PACIFIC NORTHWEST
41
Key to the Species of Pacific Northwest Perlomyia
Males
(Figure 13)
Supra-anal process ending in a broad, bluntly tipped blade ; dorsal process
collaris
of cerci slightly expanded and squarely cut off at the tip
Supra-anal process with a slender pointed tip ; dorsal process of cerci
utahensis
pointed
Key to the Species of Pacific Northwest Perlomyia
Females
(Figure 13)
Posteroventral margin of the 7th sternite little swollen, without hairs or
collaris
with hairs no longer than those of the remainder of the sternite
Posteroventral margin of the 7th sternite swollen, bearing longer and denser
utahensis
hairs than the remainder of the sternite
Perlomyia collaris Banks (Figure 13).
1906. Perlomyia collaris Banks, Can. Ent. 38 :338, description of female.
1925. Perlomyia collaris, Needham and Claassen, Monog. Plecop., p. 235 ; female
genitalia, p. 375, figure 6.
1936. Perlomyia solitaria Frison, Ann. Ent. Soc. Amer. 29 :261, male; male genitalia, pl. 2, figures 24-27.
1936. Perlomyia sobrina Frison, ibid., 29 :262, female; female genitalia, pl. 2,
figure 28.
1943. Perlomyia collaris, Ricker, Stoneflies SW B.C., pp. 82-83 ; above synonymy
indicated.
1954. Perlomyia collaris, Jewett, Jour. Fish. Res. Bd. Can. 11(5) :545 ; description
and figures of nymph.
Geographic range : Type locality: Wellington, British Columbia. Southern British
Columbia to California. Creeks and rivers. February-April. Common.
Perlomyia utahensis Needham and Claassen (figure 13).
1925. Perlomyia utahensis Needham and Claassen, Monog. Plecop., pp. 235-236,
male ; wing, p. 355, figure 5 ; male genitalia, p. 377, figures 1-2.
1938. Perlomyia utahensis, Hoppe, Univ. Wash. Publ. Biol. 4:163; description of
female.
Geographic range : Type locality: Logan, Utah. Southern British Columbia to Oregon; Utah. April-May. Rare.
Subfamily CAPNIINAE
Since most species of this family emerge during the winter season when
few other insects are on the wing, they are not commonly taken by entomologists unless specifically sought. Actually, many species of the genus Capnia
are extremely abundant in January and February on concrete bridges over
streams, and frequently several species can be secured at one location. There
are probably still a number of undiscovered species of this subfamily in this
region. The nymphs of few are known, and our knowledge of the females is
too limited to construct a key for their determination.
STONEFLIES OF THE PACIFIC NORTHWEST
42
Key to the Species of Pacific Northwest Capnia
Males
(venosa undescribed)
(Figures 14, 15, 16)
Supra-anal process slender, completely divided into a dorsal and a ventral
part, the tips of each of which are furcate
colunibiana
Supra-anal process often slender, not divided
2
2 (1). Supra-anal process directed backward
erecta
Supra-anal process directed forward
3
3 ( 2 ). Supra-anal process much expanded at the middle in dorsal view, about
half as wide as long
4
Supra-anal process slender and tapered, or, if expanded, the greatest width
less than a third of the total length
5
4 ( 3 ). Eighth tergite with a median elevation which is notched at the tip in side
view ; no knob on the 7th tergite; supra-anal process lacking long bris1.
tles
excavata
Eighth tergite without a median elevation; 7th tergite with a knob; supraanal process fringed dorsally with long, forward-pointing bristles
tumida
5 ( 3 ). Three pairs of processes on abdominal tergites
6
Less than 3 pairs of processes on tergites, if any
7
6 ( 5 ). Bilobed processes on the posterior borders of tergites 4, 5, and 6
jewetti
Pairs of processes on tergites 5, 6, and 7
sextuberculata
7 ( 5 ). A conspicuous hump or process on tergite 7
8
No hump on 7th tergite except in gracilaria, licina, and promota where
there is a low, inconspicuous one
11
8 ( 7 ). Supra-anal process expanded at the middle in dorsal view, its greatest width
nearly a third of its length
elevata
Supra-anal process not expanded in dorsal view, its greatest width much
less than a third of its length
9
9 ( 8 ). Supra-anal process reaching to 7th tergite, not slender in both lateral and
dorsal views
Supra-anal process reaching to the hind margin of the 8th tergite
p etil/a0
10 ( 9 ). Supra-anal process concave upward, not expanded toward tip in lateral
view
elongata
Supra-anal process not concave upward, expanded toward tip in lateral
view
cygna
11 (7 ). A hump or process on 8th tergite
No hump on 8th tergite
12 (11). Hump on the 8th tergite rather low, at or anterior to the middle of the ter-
12
19
gite in side view
13
Hump on the 8th tergite high and set behind the middle of the tergite
16
13 (12). Supra-anal process reaching to about the middle of the 9th tergite
nana
Supra-anal process longer
14
14 (13). Supra-anal process reaching the tubercle of the 8th tergite, scarcely curved
throughout its length, its tip upturned
15
Supra-anal process scarcely reaching the tubercle of the 8th tergite, but
concave upward sharply, the tip upturned
licina
15 (14). Supra-anal process very slender in dorsal view
gracilaria
Supra-anal process slender but expanded near tip in dorsal view
promota
16 (12). Hump on the 8th tergite set at the tergite's margin, overhanging the
9th
umpgua
Hump of the 8th tergite with its apex somewhat anterior to the hind margin
17
STONEFLIES OF THE PACIFIC NORTHWEST
43
oregona
17 (16). Supra-anal process slightly twisted near the tip in dorsal view
18
Supra-anal process always directed straight forward in dorsal view
18 (17). Supra-anal process in dorsal view with a slight enlargement at the tip
coloradensis
(Colorado, Montana, and Alaska)
Supra-anal process with an elliptical enlargement toward the tip in dorsal
melia
view, twice as broad as the narrow part nearer the base
20
19 (11). Supra-anal process blunt or merely pointed at the tip
Supra-anal process with a definite acute spine at the tip, marked off from
24
the process in both dorsal and lateral views
20 (19). Ninth tergite with longitudinal raised tubercles on either side of a median
21
membranous area
22
Ninth tergite without such tubercles beside the membranous area
21 (20). Supra-anal process asymmetrically turned to left and extended forward
glabra
over posterior third of 8th tergite
Supra-anal process straight and extended forward only about half way
willametta
across 9th tergite
22 (20). Supra-anal process reaching the hind margin of the 7th tergite; brachypterous
Supra-anal process shorter ; brachypterous or long-winged
zukeli
23
lineata
23 (22). Wings brachypterous
confusa
Wings of normal length
24 (19). Spine at the tip of the supra-anal process continuous with the dorsal margin
oenone
of the process; process bent abruptly near the middle
Spine at the tip of the supra-anal process not continuous with the dorsal
25
margin of the process ; process not bent abruptly near the middle
25 (24). Spine at the tip of the supra-anal process continuous with the ventral margin of the process ; the supra-anal process about 1/6 as wide as long .... projecta
Spine at the tip of the supra-anal process nearly median in position; the
porrecta
supra-anal process about 1/10 as wide as long
Capnia columbiana Claassen (figure 14).
1924. Capnia columbiana Claassen, Can. Ent. 56:47; description of male and female.
1925. Capnia columbiana, Needham and Claassen, Monog. Plecop., p. 265, male and
female; male and female genitalia, p. 389, figures 6-7.
1955. Capnia columbiana, Jewett, Wasmann Jour. Biology, 13 (1) ; 146-147, male
and female genitalia; p. 153, figures 2 and 2A.
Geographic range : Type locality : Terrace, British Columbia. Southern British Co-
lumbia to Montana, Utah, and Oregon. Creeks and rivers. January-March.
Common.
Discussion : There is much variation in the shape of the male supra-anal process and
in the female subgenital plate. Further, brachypterous males occur in western
Montana. The coastal form does not appear to vary greatly, however, and
only long-winged material has been collected. The only species with which
C. columbiana could be confused, C. distincta Frison, which occurs in Montana and Wyoming, differs in having the lower part of the male supra-anal
about twice as long as the upper.
Capnia confusa Claassen
1929. Capnia nivalis Neave, Contr. Can. Biol. Fish. 4:163, male and female.
1936. Capnia confusa Claassen, Ann. Ent. Soc. Amer. 29:623, new name.
Geographic range : Type locality: Maligne Lake, Alberta. Alberta and British Columbia south to Montana and Wyoming. Creeks. March-May. Common.
STONEFLIES OF THE PACIFIC NORTHWEST
44
Capnia cygna Jewett (figure 14).
1954. Capnia cygna Jewett, Jour. Fish. Res. Bd. Can. 11(5) :546; description and
figure of male.
e
J
Figure 14. Male terminalia of Capnia in lateral view, a, columbiana; b, cygna;
c, elevata; d, elongata; e, excavata; f, erecta; g, glabra; h, gracilaria; i, jewetti;
j, licina; k, lineata. (c, i, Frison, 1942a; k, Hansen, 1943a; b, Jewett, 1954a; f,
Jewett, 1955; j, Jewett, 1954b; a, d, e, g, h, Needham and Claassen, 1925).
STONEFLIES OF THE PACIFIC NORTHWEST
45
Geographic range: Type locality: The male holotype and single male paratype are
without labels. The types may have been collected at Rock Lake, Whitman
County, Washington. Presumably creeks. Late winter. Rare.
Capnia elevata Frison (figure 14).
1942. Capnia elevata Frison, Pan-Pac. Ent. 18(2) : 64-65, male and female; male
and female genitalia, figures 8a-8c.
Geographic range: Type locality: Marks Creek, Corvallis, Oregon. Washington and
Oregon. Creeks. February-March. Rare.
Capnia elongata Claassen (figure 14).
1924. Capnia elongata Claassen, Can. Ent. 56:56; description of male.
1925. Capnia elongata, Needham and Claassen, Monog, Plecop., p, 260, male genitalia, p, 387, figure 7.
1943. Capnia elongata, Ricker, Stoneflies SW B.C., p. 99, description and figure of
female genitalia.
Geographic range : Type locality: Near Caribou, Plumas County, California. British
Columbia to California, Rivers, February-March, Common.
Capnia erecta Jewett (figure 14).
1955. Capnia erecta Jewett, Wasmann Jour. Biol. 13(1) : 147, male.
Geographic range: Type locality: Grave Creek, tributary of Rogue River, at U. S.
Highway 99, Josephine County, Oregon. Known only from the holotype.
Creeks. March. Rare.
Discussion: This is the only described species in the genus with a long, caudally
directed supra-anal process.
Capnia excavata Claassen (figure 14),
1924. Capnia excavata Claassen, Can. Ent. 56:47; description of male.
1925. Capnia excavata, Needham and Claassen, Monog, Plecop., pp. 260-261, male;
male genitalia, p. 387, figure 8.
1937. Capnia excavata, Frison, Bull. Ill. Nat. Hist. Sur. 21:87, figure 75, description
and figure of female genitalia.
Geographic range : Type locality: Feather River Canyon near Caribou, Plumas
County, California. British Columbia to California. Creeks and rivers. January-April. Abundant.
Capnia glabra Claassen (figure 14).
1924. Capnia glabra Claassen, Can. Ent. 56 :55; description of male.
1925. Capnia glabra, Needham and Claassen, Monog. Plecop., p, 258, male; male
genitalia, p. 387, figure 4.
Geographic range: Type locality: Sunnyside Mine, Plumas County, California. California and Oregon, Creeks. February-April. Rare.
Capnia gracilaria Claassen (figure 14).
1924. Capnia gracilaria Claassen, Can. Ent. 56:57; description of male.
1925. Capnia gracilaria, Needham and Claassen, Monog. Plecop., p. 258, male; male
genitalia, p. 387, figure 5.
1943. Capnia gracilaria, Ricker, Stoneflies SW B.C., pp. 99-100, female and nymph;
female genitalia, p, 101, figure 82.
Geographic range: Type locality: Aweme, Manitoba. British Columbia and Manitoba
south to Montana and Oregon. Creeks, small rivers. February-April. Abundant.
Discussion: This species resembles C. promota Frison from which it can be distinguished in the male by its more slender supra-anal process. The two species
apparently occupy different areas, C, promota occurring west of the Cascades,
C. gracilaria, east of the Cascades.
STONEFLIES OF THE PACIFIC NORTHWEST
46
Capnia jewetti Frison (figure 14).
1942. Capnia jewetti Frison, Pan-Pac. Ent. 18(2) :63, description and figures of
male and female, figures 6a-6b.
Geographic range: Type locality : Muddy Creek, 14 miles south of Corvallis, Oregon.
Western Oregon. Creeks. small rivers. February-April. Common.
Capnia licina Jewett (figure 14).
1954. Capnia licina Jewett, Pan-Pac. Ent. 30(3) :174-175, description and figure
of male.
b
Figure 15. Male terminalia of Capnia in lateral view. a, melia; b, nana; c, ore-
gona; d, petila; e, porrecta; f, projecta; g, promota; h, sextuberculata. (f, g,
Frison, 1937; a, c, Frison, 1942a; d, e, h, Jewett, 1954a; b, Needham and Claassen, 1925).
STONEFLIES OF THE PACIFIC NORTHWEST
47
Geographic range: Type locality : Small creek at junction of Oregon highways 36
and 50, Clackamas County, Oregon. Known only from the holotype male.
Small creeks. March-April. Rare.
Capnia lineata Hanson (figure 14).
1943. Capnia lineata Hanson, Proc. Ent. Soc. Wash. 45(4) :85-86, male and female;
male and female genitalia, p. 87, figures 2-3.
Geographic range: Type locality : Troy, Idaho. Idaho and California. Presumably
creeks. March-April. Rare.
Discussion: This species resembles C. confusa in the shape of the male supra-anal
process, but the holotype male is brachypterous. The female subgenital plates
appear to be different, that of C. confusa having a distinct prolongation medially, that of lineata scarcely extended.
Capnia melia Frison (figure 15).
1942. Capnia melia Frison, Pan-Pac. Ent. 18(2) :61, male and female; male and
female genitalia, p. 62, figures 5a-5c.
1943. Capnia melia, Ricker, Stoneflies SW B.C., pp. 101-102, male and female;
wing, p. 101, figure 74; male and female genitalia, p. 101, figures 75, 79,
and 81.
Geographic range: Type locality : Wildcat Creek, tributary of Sandy River, Clackamas County, Oregon. British Columbia to Oregon. Creeks. January-April.
Abundant.
Capnia nana Claassen (figure 15).
1924. Capnia nana Claassen, Can. Ent. 56 :46; description of male.
1925. Capnia nana, Needham and Claassen, Monog. Plecop., pp. 257-258, male; male
genitalia, p. 387, figure 3.
1942. Capnia nana, Frison, Pan-Pac. Ent. 18(2) :66-68, female; female genitalia,
p. 67, figure 11.
Geographic range: Type locality : Terrace, British Columbia. British Columbia south
to Oregon and Utah. Creeks, small rivers. February-April. Common.
Capnia oenone Neave
1929. Capnia oenone Neave, Contr. Can. Biol. Fish. 4:162, male and female.
Geographic range: Type locality : Jacques Lake, Alberta. Alberta, British Columbia
to Montana. Creeks and rivers. March-May. Common.
Capnia oregona Frison (figure 15).
1942. Capnia oregona Frison, Pan-Pac. Ent. 18(2) :63-64, male; male genitalia,
p. 62, figures 7a-7b.
1954. Capnia oregona, Jewett, Pan-Pac. Ent. 30(3) :175, description and figure of
female.
Geographic range: Type locality: Muddy Creek, 14 miles south of Corvallis, Benton
County, Oregon. Western Oregon. Creeks. February-April. Rare.
Capnia petila Jewett (figure 15).
1954. Capnia petila Jewett, Jour. Fish. Res. Bd. Can. 11(5) :546, description and
figure of male.
Geographic range: Type locality: Spring Creek, tributary to Powder River, Baker
County, Oregon. Known only from the type locality. Creeks. March-April.
Rare.
Capnia porrecta Jewett (figure 15).
1954. Capnia porrecta Jewett, Jour. Fish. Res. Bd. Can. 11(5) :546-547, description
and figure of male.
Geographic range: Type locality : Santiam River near Jefferson, Linn County, Oregon. Western Oregon and California. Rivers and creeks. October-December.
Common.
STONEFLIES OF THE PACIFIC NORTHWEST
48
Capnia projecta Frison (figure 15).
1937. Capnia projecta Frison, Bull. Ill. Nat. Hist. Sur. 21:87 -88; description of
male and female; male and female genitalia, figure 76.
1943. Capnia projecta Ricker, Stoneflies SW B.C., p. 103; male genitalia, p. 101,
figures 76-78.
Geographic range: Type locality : Corvallis, Oregon. Alaska to California. Creeks
rivers. September-April. Abundant.
Discussion: Considerable variation is exhibited in material presently assigned to this
specific name, from various locations along the Pacific Coast. Typical material
is found in British Columbia and Oregon during late autumn and winter and
occasionally in early spring. Specimens taken at some localities in Oregon during March and April have less pigmented wings and may represent an undescribed species. C. porrecta has wings of a similar pigmented pattern but is
differentiated by the more slender supra-anal process.
Capnia promota Frison (figure 15).
1937. Capnia promota Frison, Bull. Ill. Nat. Hist. Sur. 21 : (3) :88-89, male and female; male and female genitalia, p. 88, figure 77.
Geographic range: Type locality: Corvallis, Oregon. Washington to California.
Creeks. January-April. Abundant.
Capnia sextuberculata Jewett (figure 15).
1954. Capnia sextuberculata Jewett, Jour. Fish. Res. Bd. Can. 11(5) :547-548, description and figure of male.
Geographic range: Type locality : Spring Creek, tributary to Powder River, Baker
County, Oregon. Known only from the type locality. Creeks. March-April.
Rare.
Capnia tumida Claassen (figure 16).
1924. Capnia tumida Claassen, Can. Ent. 56:47-48; description of male.
1925. Capnia tumida, Needham and Claassen, Monog. Plecop., pp. 261-262, male;
male genitalia, p. 387, figure 9.
1942. Capnia tumida, Frison, Pan-Pac. Ent. 18:65; male and female genitalia, p. 67,
figures 10a-10c.
Geographic range: Type locality : Sunnyside Mine near Seneca, Plumas County,
California. California and Oregon. Creeks. January-March. Common.
Capnia umpqua Frison (figure 16).
1942. Capnia umpqua Frison, Pan-Pac. Ent. 18(2) :65, male and female; male and
female genitalia, p. 62, figures 9a-9c.
Geographic range: Type locality : Umpqua River, Douglas County, Oregon. Western
Oregon and California. Creeks and rivers. February-April. Common.
Capnia venosa (Banks) (figure 16).
1900. Capnura venosa Banks, Trans. Amer. Ent. Soc. 26 :245 ; female.
1925. Capnura venosa, Needham and Claassen, Monog. Plecop., pp. 270-271; female
genitalia, p. 389, figure 13; wings, p. 385, figure 7.
1946. Capnia venosa, Hanson, Amer. Midland Nat. 35(1) :229; placed in genus
Capnia.
Geographic range: Type locality : Pullman, Washington. Washington and Oregon.
Presumably creeks. March-April. Rare.
Discussion: This species is readily recognized by the crossveins in the forewing.
Capnia venosa is apparently fairly common in the vicinity of Pullman, Washington. It is remarkable that the male has not been collected with the female,
but it may be brachypterous and consequently overlooked by the general collector.
STONEFLIES OF THE PACIFIC NORTHWEST
49
Capnia willametta Jewett (figure 16).
1955. Capnia willametta Jewett, Wasmann Jour. Biol. 13(1) :147-148, description
and figure of male.
Geographic range : Type locality: Dixon Creek, Benton County, Oregon. Known
only from the vicinity of Corvallis, Oregon. Creeks. December. Rare.
Capnia zukeli Hanson (figure 16).
1943. Capnia zukeli Hanson, Proc. Ent. Soc. Wash. 45(4) :86, male and female ;
male and female genitalia, p. 87, figures 4 and 5.
Geographic range: Type locality: Moscow, Idaho. Known only from the types from
Moscow, Idaho. Presumably creeks. March-April. Rare.
Key to the Species of North American Eucapnopsis
Males
(Figure 17)
Supra-anal process with a broad, bulging tip on which are two small
horns
Supra-anal process with a slender, erect tip lacking horns
brevicauda
vedderensis
Figure 16. Male terminalia of Capnia in lateral view and wing of Capnia
venosa. a, tumida; b, umpqua; c, willametta; d, zukeli; e, venosa. (b, Frison,
1942a; d, Hanson, 1943a; c, Jewett, 1955; a, e, Needham and Claassen, 1925).
STONEFLIES OF THE PACIFIC NORTHWEST
50
Key to the Species of North American Eucapnopsis
Females
(Figure 17)
Eighth sternite membranous posteriorly with a narrow sclerotized area extending into the membrane from either side
brevicauda
Eighth sternite completely membranous posteriorly
vedderensis
Eucapnopsis brevicauda (Claassen) (figure 17).
1924. Capnia brevicauda Claassen, Can. Ent. 56 :55 ; description of female.
1925. Capnia brevicauda, Needham and Claassen, Monog. Plecop., p. 269 ; wing, p.
385, figure 2; female genitalia, p. 387, figure 12.
1934. Eucapnopsis brevicauda, Neave, Can. Ent. 66 :6 ; description of male.
1937. Eucapnopsis brevicauda, Frison, Bull. Ill. Nat. Hist. Sur. 21 :86 ; male and
female genitalia, figure 73.
1943. Eucapnopsis brevicauda, Ricker, Stoneflies SW B.C., pp. 85 -86; description
of nymph.
Geographic range : Type locality : Boulder, Colorado. British Columbia to Colorado
and California. Creeks and rivers. February-May. Abundant.
Eucapnopsis vedderensis Ricker (figure 17).
1943. Eucapnopsis vedderensis Ricker, Stoneflies SW B.C., pp. 86, 87, male and
female ; male and female genitalia, p. 88, figures 52-55.
Geographic range : Type locality : Chilliwack River at Vedder Crossing, British Columbia. British Columbia and Montana. Creeks and rivers. April-May. Common.
Key to the Species of Pacific Northwest Isocapnia
Males
(Figure 18)
Supra-anal process shaped like a bird's head ; a pair of humps on tip of 9th
2
tergite
Supra-anal process slender, not expanded beyond the base ; no humps on 9th
3
tergite
spenceri
2 ( 1 ). Wings of normal length
spenceri var. thujae
Wings almost wanting
1.
a
b
Figure 17. Terminalia of Eucapnopsis. a, b, brevicauda; c, vedderensis. a, lat-
eral view of male; b, ventral view of female; c, dorsal view of male. (a, b,
Frison, 1937; c, Ricker, 1943).
STONEFLIES OF THE PACIFIC NORTHWEST
51
3 (1). Tip of supra-anal process short, not exceeding the length of the basal cercal
segment
abbreviata
Tip of supra-anal process more than twice as long as the basal cercal seg4
ment
4 ( 3 ). Tip of the supra-anal process slightly concave forward, as viewed from the
side
Tip of supra-anal process weakly S-shaped in side view
agassizi
grandis
Isocapnia abbreviata Frison (figure 18).
1942. Isocapnia abbreviata Frison, Pan-Pac. Ent. 18(2) :71-72; male genitalia, p. 67,
figures 17a-17c.
1954. Isocapnia abbreviata, Jewett, Jour. Fish. Res. Bd. Can. 11(5) :548, description and figure of female.
Geographic range: Type locality: Oak Creek, Benton County, Oregon. Oregon and
California. Creeks and rivers. February-April. Rare.
Figure 18. Terminalia of Isocapnia. a, b, abbreviata; c, d, agassizi; e, grandis;
f, spenceri; g, thujae. a, dorsal view of male; b, d, ventral view of female; c, e,
f, g, lateral view of male. (a, Frison, 1942a; b, Jewett, 1954a; c, d, f, g, Ricker,
1943).
52
STONEFLIES OF THE PACIFIC NORTHWEST
Isocapnia agassizi Ricker (figure 18).
1943. Isocapnia agassizi Ricker, Stoneflies SW B.C., pp. 90-91, male and female;
male and female genitalia, wing, p. 88, figures 58, 62, 63, 65, 66.
Geographic range : Type locality : Ferry slip, Fraser River near Agassiz, British
Columbia. British Columbia to Oregon. Rivers. March-April. Rare.
Isocapnia grandis (Banks) (figure 18).
1908. Arsapnia grandis Banks, Can. Ent. 37:329; description of male.
1925. Capnia grandis, Needham and Claassen, Monog. Plecop., pp. 259-260; male
genitalia, p. 387, figure 6.
1937. Capnia fumigata Claassen, Can. Ent. 69 :79; description of male and female.
1938. Isocapnia fumosa Banks, Psyche 45(1) :74; description of female.
1943. Isocapnia grandis, Hanson, Bull. Brooklyn Ent. Soc. 38(5) :158-159; male and
female genitalia, p. 161, figures 3-5.
1943. Isocapnia grandis, Ricker, Stoneflies SW B.C., p. 89; nymph, figures 56, 59,
60; wing, figure 61 ; male genitalia, figures 57 and 64.
Figure 19. Male terminalia of Brachyptera and Taeniopteryx. a, occidentalis;
b, oregonensis; c, nigripennis; d, maura; e, pacifica; f, pallida. a-d, lateral view;
e-f, dorsal view. (a-e, Needham and Claassen, 1925; f, Ricker, 1943).
STONEFLIES OF THE PACIFIC NORTHWEST
53
Geographic range : Type locality : Victoria, British Columbia. Alaska to California.
Creeks and rivers. February-May. Common.
Isocapnia spenceri Ricker (figure 18).
1943. Isocapnia spenceri Ricker, Stoneflies SW B.C., pp. 92-93, male and female;
wing, male and female genitalia, p. 93, figures 67-71.
Geographic range: Type locality : Chilliwack River at Vedder Crossing, British Columbia. British Columbia to California. Rivers. March-May. Common.
Discussion: The variety thujae differs in having short wings (males) and slight
differences in the shape of the male genitalia.
Subfamily TAENIOPTERYGINAE
Members of this subfamily frequently occur with species of Nernoura in
streams of various sizes. Brachyptera Pacifica occurs in such large streams as
the Snake River, and adults are taken in association with Arcynopteryx par-
allela and Isogenus frontalis colubrinus. Taeniopteryx inaura occurs in
streams with considerable amounts of organic detritus on the bottom and is
one of a few stoneflies which occur in eastern and midwestern United States
as well as on the Pacific Coast. The nymphs of the western members of the
subfamily are little known so no key is presented for their identification,
Key to the Subgenera and Species of Pacific Northwest
Brachyptera
Males (females, by color)
(Figure 19)
1.
Two ocelli; wings spotted; first cubital vein in forewing with 4 or 5
branches; a median keel present near the end of the subgenital plate
occidentalis
(Subgenus Doddsia)
Three ocelli; wings not spotted; first cubital vein in the forewing with 2
branches; no keel near the end of the subgenital plate
2
(Subgenus Taenionema)
2 (1). Wings often heavily infuscated; frequently red or orange pigment on ab-
dominal segments; supra-anal process of male gradually tapering to a
point; 10th tergite of male without 2 raised, rearward pointing appendages
nigripennis
Wings never heavily infuscated though there may be an infuscated area in
the vicinity of the cord; red or orange pigment usually absent from abdominal segments; supra-anal process of male not tapering to a point but modi3
fied distally; 10th tergite of male with 2 rearward pointing appendages
3 ( 2 ). Wings lightly infuscated; supra-anal process of male deeply emarginate
oregonensis
behind when viewed from above
Wings hyaline or with an infuscated band in the area of the cord; supraanal process of male not deeply emarginate behind when viewed from above 4
4 ( 3 ). Wings hyaline; lobes at base of male 10th tergite long, separated at the
pallida
base by a distance no more than their length
Wings with a pigmented band in the area of the cord; lobes at the base of
the male 10th tergite short, separated at the base by a distance 2 or 3 times
Pacifica
their length
STONEFLIES OF THE PACIFIC NORTHWEST
54
Brachyptera (Doddsia) occidentalis (Banks) (figure 19).
1900. Taeniopteryx occidentalis Banks, Trans. Amer. Ent. Soc., 24:244; description of female.
Taeniopteryx occidentalis, Needham and Claassen, Monog. Plecop., pp. 250251 ; wings, p. 357, figure 3; male genitalia, p. 381, figures 1-2 ; female genitalia, p. 383, figure 1.
Geographic range : Type locality : Mount Rainier, Washington. Alaska to California
1925.
and Colorado.
Brachyptera (Taenionema) nigripennis (Banks) (figure 19).
1918. Taeniopteryx (Rhabdiopteryx) nigripennis Banks, Bull. Mus. Comp. Zool.
62 (1) :8.
1925. Taeniopteryx nigripennis, Needham and Claassen, Monog. Plecop., p. 245;
male genitalia, p. 381, figures 7 -8; female genitalia, p. 383, figure 4.
1943.
Taeniopteryx (Taenionema) nigripennis, Ricker, Stoneflies SW B.C., pp. 53-
54 ; description of male nymph.
Geographic range : Type locality : Wenatchee, Washington. British Columbia and
Alberta to Colorado and California. Creeks and rivers. March-May. Abundant.
Brachyptera (Taenionema) oregonensis (Needham and Claassen) (figure 19).
1925.
Taeniopteryx oregonensis, Needham and Claassen, Monog. Plecop., pp. 248249 ; male genitalia, p. 379, figures 7-8.
1942. Brachyptera oregonensis, Frison, Bull. Ill. Nat. Hist. Sur. 22(2) :251 ; description and figure of female.
Geographic range : Type locality : Corvallis, Oregon. Washington and Oregon.
Creeks and rivers. February-April. Abundant.
Brachyptera (Taenionema) pacifica (Banks) (figure 19).
1900. Taeniopteryx pacifica Banks, Trans. Amer. Ent. Soc. 26:244.
1918. Taeniopteryx pacifica, Newcomer, Jour. Ag. Res. 13(1) :37-41 ; figures of
male, female, and nymph.
1925. Taeniopteryx pacifica, Needham and Claassen, Monog. Plecop., p. 246; wing,
p. 357; male genitalia, p. 381, figures 11-12; female genitalia, p. 383, figure 3.
Geographic range : Type locality: Pullman, Washington. British Columbia and Alberta to Colorado and California ; Labrador to Virginia. Rivers. FebruaryApril. Abundant.
Brachyptera (Taenionema) pallida (Banks) (figure 19).
1902. Nemoura pallida Banks, Can. Ent. 34:125; female.
1918. Taeniopteryx pallida Banks, Bull. Mus. Comp. Zool. 62(1) :9 (redescribed as
a new species).
1925. Taeniopteryx banksii, Needham and Claassen, Monog. Plecop., p. 249 (new
name for pallida Banks 1918).
1925. Taeniopteryx pallida, Needham and Claassen, ibid., p. 250.
1936. Nemoura pallidura Claassen, Ann. Ent. Soc. Amer. 29 :623 (new name for
AT pallida Banks 1902).
1938.
Taeniopteryx kincaidi Hoppe, Univ. Wash. Publ. Zool. 4:164; description and
figures of male and female.
1942. Brachyptera pacifica, Frison (in part), Bull. Ill. Nat. Hist. Sur. 22:251 (not
pacifica Banks).
Taeniopteryx (Taenionema) kincaidi, Ricker, Stoneflies SW B.C., pp. 52 -53;
description of nymph.
1952. Brachyptera (Taenionema) pallida, Ricker, Syst. Studies Plecop., pp. 158 -159;
above synonymy indicated.
Geographic range : Type locality : Little Beaver, Colorado. British Columbia to Colorado and California. Creeks and rivers. April-June. Common.
1943.
STONEFLIES OF THE PACIFIC NORTHWEST
55
Discussion: This species differs from B. pacifica (Banks) in both sexes in having
clear wings and in the males by the character described in the key. B. pacifica
is rarely taken at small streams where B. pallida occurs most commonly. Both
species occur in the Wenatchee River, Washington.
Taeniopteryx maura (Pictet) (figure 19).
1841. Nernoura maura Pictet, Famille des perlides; description of female.
1847. Taeniopteryx nivalis Fitch, Emmons Jour. Agri. Sci. 5:274.
1925.
Taeniopteryx ntaura, Needham and Claassen, Monog. Plecop., pp. 239-240;
wing, p. 357, figure 4; male genitalia, p. 379, figures 5 and 6; female geni-
talia, p. 383, figure 7.
Taeniopteryx nivalis, Needham and Claassen, ibid., pp. 240-241.
1931. Taeniopteryx nivalis, Claassen, Plecop. Nymphs, pp. 103-104; figures of
1925.
nymph.
1931.
1942.
Taeniopteryx maura, Claassen, ibid., pp. 104-105; nymph.
Taeniopteryx maura, Frison, Bull. Ill. Nat. Hist. Sur. 22(2) :248; synonymy.
Geographic range : Type locality: Pennsylvania. Eastern North America, Minnesota,
Oregon, and California. Creeks and rivers. January-March. Abundant.
Family PTERONARCIDAE
Members of this family include the largest North American stoneflies
belonging to the genus Pteronarcys. The recorded species are all common
though Pteronarcella is less often encountered than Pteronarcys. Nymphs of
Pteronarcys are frequently abundant in medium sized rivers, and the adults
may occasionally be seen flying in great numbers across highways paralleling
large streams.
Key to the Genera and Species of Pacific Northwest
Pteronarcidae
Males
(Figure 20)
2
(Genus Pteronarcella)
Abdominal gills on first 3 segments
3
(Genus Pteronarcys)
Abdominal gills on first 2 segments only
2 (1). The recurved, scoop-shaped appendage on dorsum of the 9th abdominal segregularis
ment acutely pointed at the apex and its side margins straight
1.
The appendage on the dorsum of the 9th abdominal segment broadly
rounded at the apex and its side margins sinuous
(Rocky Mountain region)
badia
3 (1). Ninth abdominal sternite prolonged backward far beyond the tip of the
10th segment and bifid at the tip of the prolongation
dorsata
(Northern regions)
4
Ninth abdominal sternite truncate, but little produced and entire on tip
4 ( 3 ). Erect lobes of the divided 10th tergite rather broadly rounded, about as
californica
high as wide
Erect lobes of the divided 10th tergite rather narrow, much higher than
wide
Princeps
56
STONEFLIES OF THE PACIFIC NORTHWEST
Key to the Genera and Species of Pacific Northwest
Pteronarcidae
Females
(Figure 20)
1.
Abdominal gills on first 3 segments
Abdominal gills on first 2 segments only
(Genus Pteronarcella)
(Genus Pteronarcys)
2
3
2 (1). Hind margin of subgenital plate acutely notched
regularis
Hind margin of the subgenital plate rounded, truncate, somewhat trilobate,
but never acutely notched
(Rocky Mountain region)
badia
3 (1). Posterior margin of the subgenital plate but little produced backward
(Northern regions)
dorsata
Posterior margin of the subgenital plate conspicuously extended backward 4
4 ( 3 ). Processes of subgenital plate somewhat equilateral triangles approximated
at base
californica
Processes very elongated triangles, twice as high as broad and more widely
separated at base
princeps
C
d
h
Figure 20. Terminalia of Pteronarcys and Pteronarcella. a, b, regularis; c, d,
badia; e, f, californica; g, h, princeps. (Needham and Claassen, 1925).
STONEFLIES OF THE PACIFIC NORTHWEST
57
Key to the Genera and Species of Pacific Northwest
Pteronarcidae
Nymphs
1.
Abdominal gills on first 3 segments
Abdominal gills on first 2 segments only
(Genus Pteronarcella)
(Genus Pteronarcys)
2
3
2 (1). Filaments of gill tufts less than twice as long as the basal conical process
of gill tufts
regularis
Filaments of gill tufts at least twice as long as the bases of the gill tufts
3
(Rocky Mountain region)
( 1 ). Lateral prothoracic teeth long, slender, sharp, and directed outward ; supra-badia
antennal plate prolonged into a sharp tooth; wing pads pointed
californica
Lateral prothoracic teeth short and not directed outward so much; supraantennal plate blunt ; wing pads rounded
4
4 ( 3 ). Prothoracic teeth usually as long as wide; 9th sternite of male produced
beyond the 10th; 10th tergite of female nearly straight
(Northern regions)
dorsata
Prothoracic teeth usually shorter than wide; 9th sternite of male narrow
and not produced; 10th tergite of female with the apex considerably elevated
princeps
Pteronarcella regularis (Hagen) (figure 20).
1873. Pteronarcys regularis Hagen, Bull. Geol. Sur. Colo., p. 573.
1925. Pteronarcella regularis, Needham and Claassen, Monog. Plecop., pp. 45-56;
male genitalia, p. 305, figure 15 ; female genitalia, p. 307, figures 3-5.
1931. Pteronarcella regularis, Claassen, Plecop. Nymphs, pp. 36-37; description and
figures of nymph.
Geographic range: Type locality : Nevada. Alaska to California and Nevada. Creeks,
small rivers. April-June. Common.
Discussion: The other described species of this genus, P. badia (Hagen), is common
in the Rocky Mountain states. The key characters readily separate the two
species.
Pteronarcys (Pteronarcys) californica Newport (figure 20).
1848. Pteronarcys californica Newport, Proc. Linn. Soc. 1:388.
1925. Pteronarcys californica, Needham and Claassen, Monog. Plecop., pp. 37-38;
male and female genitalia, p. 305, figures 5 and 6.
1931. Pteronarcys californica, Claassen, Plecop. Nymphs, p. 32; description and figures of nymph.
Geographic range: Type locality : California. British Columbia to California and
Montana to New Mexico. Creeks and rivers. April-June. Abundant.
Pteronarcys (Pteronarcys) princeps Banks (figure 20).
1907. Pteronarcys princeps Banks, Can. Ent. 39:327; description of male and female.
1925. Pteronarcys princeps, Needham and Claassen, Monog. Plecop., p. 38; male
and female genitalia, p. 305, figures 7 and 8.
1931. Pteronarcys princeps, Claassen, Plecop. Nymphs, p. 33, description and figures
of nymph.
Geographic range: Type locality: Mission, British Columbia. British Columbia to
California. Creeks and rivers. April-June. Common.
58
STONEFLIES OF THE PACIFIC NORTHWEST
Suborder SETIPALPIA
Family PERLODIDAE
This family was recently revised by Ricker (1952) whose arrangement
of subfamilies and generic concepts differs in many details from those of
earlier workers such as Klapalek (1912) and Frison (1935, 1942). Many
species are yet known only by one sex, and the nymphs of a very large number have not been described. It is necessary to base much of the classification
on the male genitalia. The keys on page 20 and 22 will place males to the
genera known to occur in the Pacific Northwest. The mesosternal ridge patterns, figure 21, offer good characters to separate many subgenera.
Key to the Subgenera and Species of Pacific Northwest
Arcynopteryx
Males (in part, nymphs)
(Figures 22, 23)
1.
Three pairs of thoracic gills and 1 pair of cervical gills; 7th tergite with
aurea
(Subgenus Perlinodes)
a bifid process
Thoracic gills present or absent, cervical gills absent; 7th tergite normal .... 2
2 ( 1 ). Gills on meso- and metathorax, absent from the prothorax ; arms of the
mesosternal Y-ridge meet the posterior corners of the furcal pits
(Subgenus Setvena)
Gills on all 3 thoracic segments, or entirely absent from the thorax ; arms
3
of the mesosternal Y-ridge meet or approach the anterior corners of the
4
furcal pits
bradleyi
3 ( 2 ). Lateral stylets slender, tapering to a single acute point
tibialis
Lateral stylets broad, with 3 or 4 short cusps at the tip
YYT
Y
f
g
e
Y
h
Figure 21. Diagrams of perlodid mesosternal ridge patterns. a, nymphs and
adults of Perlinodes; b, nymphs of several subgenera of Isogenus, nymphs and
adults of Dolkrila; c, adults of most subgenera of Isogenus and of Calliperla,
nymphs and adults of many Isoperla; d, nymphs and adults of Isogenoides; e,
nymphs and adults of Skwala, Megarcys, and (in part) Arcynopteryx, nymphs
of Frisonia; f, adult of Chernokrilus; g, adult of Osobenus; h, nymphs and
adults of Arcynopteryx (in part); i, nymphs and adults of Isoperla (in part).
(Ricker, 1952).
STONEFLIES OF THE PACIFIC NORTHWEST
59
4 ( 2 ). Gills on all 3 thoracic segments; apical crossveins commonly present from
Ri to M1 or M2
(Subgenus Megarcys)
Thoracic gills absent; apical crossveins commonly present no farther back
than the branches of R., or rarely M,
a
5
9
i
3
b
9
d
h
l
Figure 22. Terminalia of Arcynopteryx. a, b, picticeps; c, compacta; d, e,
irregularis; f, g, signata; h, j, subtruncata; i, yosemite; k, watertoni ; 1, parallela.
a, d, f, h, lateral view of male; c, k, 1, dorsal view of male; b, e, g, j, ventral
view of female; i, male hook on 10th tergite. (1, Frison, 1936; c, f, g, h, j, Hanson, 1942; b, d, e, i, Needham and Claassen 1925; a, Ricker, 1943; k, Ricker,
1952).
STONEFLIES OF THE PACIFIC NORTHWEST
60
5 ( 4 ). Genital hooks on 10th tergite expanded near the tip in side view and
broadly rounded; median patch of spinules on 9th tergite separated from
irregularis
lateral patches by a complete spinule-free area
Genital hooks not expanded, their tips pointed; median patch of spinules on
the 9th tergite not separated from the lateral patches by any completely
6
spinule-free area
6 ( 5 ). Lateral stylets of genitalia bluntly rounded at the tip with a small backward
subtruncata
pointing subacute process on the posterior corner
7
Lateral stylets narrowed gradually to a terminal acute or subacute spine
7 ( 6 ). Anterior-posterior length of the spinule patch of the 9th tergite little greater
watertoni
along the midline than on the lateral knobs
Length of the spinule patch at least 1.5 times as great in the median posi8
tion
8 ( 7 ). Spinules of the 9th tergite of almost uniform density across the entire
yosemite
area where they occur ; found above tree line in glacial streams
Spinules of the 9th tergite clearly much sparser in the anterior portion of
signata
the median patch; found in forested zone
posterior
inner
corners
of
10th
ter9 ( 4 ). Transverse mesosternal ridge present ;
gite produced into an erect, slender, acute process
picticeps
(Subgenus Frisonia)
Transverse mesosternal ridge absent ; posterior inner corners of the 10th
10
tergite blunt, spinulose
10 ( 9 ). Supra-anal process very long and needle-like; lateral stylets absent
(Eurasia,
(Subgenus Arcynopteryx)
compacta
northern North America)
Supra-anal process blunt, not usually long; lateral stylets present
11
(Subgenus Skwala)
11 (10). Dorsal hook of the 10th tergite 2 to 3 times as long as the breadth of its
constricted middle portion
Dorsal hook 4 to 5 times as long as its minimum breadth
parallela
curvata
Key to the Subgenera and Species of Pacific Northwest
Arcynopteryx
Females (in part, nymphs)
(Figures 22, 23)
1.
Three pairs of thoracic gills and 1 pair of cervical gills
(Subgenus Perlinodes)
Thoracic gills present or absent ; cervical gills absent
aurea
2 ( 1 ). Gills on meso- and metathorax, absent from the prothorax; arms of the
mesosternal Y-ridge meet the posterior corners of the furcal pits; sub(Subgenus Setvena)
genital plate entire
Gills on all 3 thoracic segments, or entirely absent from the thorax; arms
of the mesosternal Y-ridge meet or approach the anterior corners of the
2
3
4
furcal pits ; subgenital plate notched or excavated
bradleyi
3 ( 2 ). Found in the Rocky Mountains area
tibialis
Found in the Coast and Cascade Mountains area
4 ( 2 ). Gills present on all 3 thoracic segments; subgenital plate narrowly notched;
apical crossveins commonly present from R, to M1 or M2
(Subgenus Megarcys)
Thoracic gills absent; subgenital plate broadly excavated; apical crossveins
5
commonly present no farther back than the branches of R., or rarely
M1
9
STONEFLIES OF THE PACIFIC NORTHWEST
61
5 ( 4 ). Maximum length of the subgenital plate 0.7 to 1.1 times the length of the
8th segment laterad of the plate; notch of the subgenital plate at least fairly
6
long, and either narrow or broad
Maximum length of the subgenital plate 0.3 to 0.6 of the length of the
8th segment laterad of the plate; notch of the subgenital plate very short,
8
its apex narrowly rounded, and the sides of the slit close together
6 ( 5 ). Notch of the subgenital plate narrowly rounded at the apex, its sides closely
yosemite
applied; found above tree line in glacial streams
Notch of the subgenital plate broadly rounded at the apex, the sides us-
ually separated by about 0.3 of the length of the notch; found in the
forested zones
7
signata
irregularis
subtruncata
watertoni
7 ( 6 ). Found in the Rocky Mountains and adjacent ranges
Found in the Coast and Cascade Mountains
8 ( 5 ). Found in the Coast and Cascade Mountains
Found in the Rocky Mountains and adjacent ranges
C
d
h
Terminalia of Arcynopteryx. a, c, tibialis; b, d, bradleyi; e, f, curvata; g, h, aurea. a, b, g, lateral view of male; e, dorsal view of male; c, d, f, h,
ventral view of female. (Hanson, 1942).
Figure 23.
62
STONEFLIES OF THE PACIFIC NORTHWEST
9 ( 4 ). Transverse mesosternal ridge present
picticeps
(Subgenus Frisonia)
Transverse mesosternal ridge absent
10
10 ( 9 ). Found in Alpine Zone (Eurasia, northern North America)
compacta
(Subgenus arcynopteryx)
Found in temperate zones
(Subgenus Skwala)
parallela and curvata
Arcynopteryx (Frisonia) picticeps Hanson (figure 22).
1942. Arcynopteryx picticeps Hanson, Amer. Midland Nat. 28:397, description of
female; head and female genitalia, p. 405, figures 8 and 15.
1943. Arcynopteryx walkeri Ricker, Stoneflies SW B.C., pp. 118-119, description
and figures of head, pronotum, wing, male genitalia, and nymphal mouthparts,
placed in new subgenus Frisonia.
Geographic range : Type locality : Mount Rainier, Washington. Southern British
Columbia to Oregon. Rivers. April-July. Rare.
Arcynopteryx (Megarcys) irregularis (Banks) (figure 22).
1900. Dictyopteryx irregularis Banks, Trans. Amer. Ent. Soc. 26 :243; description
of female.
1925. Perlodes signata Needham and Claassen, Monog. Plecop., p. 55, male and
female ; wings, male and female genitalia, p. 309, figures 3, 7, 8; p. 311, figures
3, 6; p. 299, figures 6-10.
1943. Arcynopteryx signata irregularis, Ricker, Stoneflies SW B.C., p. 110.
Geographic range : Type locality: Mt. Rainier, Washington. Coast and Cascade
Mountains of southern British Columbia and Washington. Creeks. April-July.
Common.
Arcynopteryx (Megarcys) signata (Hagen) (figure 22).
1874. Dictyopteryx signata Hagen, Geol. Surv. Terr., Rpt. for 1873, p. 575.
1931. Perlodes signata, Claassen, Plecop. Nymphs, p. 43; description and figures of
nymph.
1942. Megarcys signata, Hanson (in part), Amer. Midland Nat., 28 :398, male and
female ; head and female genitalia, p. 405, figures 9, 16; male genitalia, p. 405,
figure 23.
Geographic range : Type locality: Colorado. Rocky Mountains and adjacent interior
ranges from northern British Columbia south to Utah, Colorado, and New
Mexico (one record for Idaho). Creeks and rivers. April-July. Common.
Arcynopteryx (Megarcys) subtruncata (Hanson) (figure 22).
1925. Perlodes irregularis, Needham and Claassen (not irregularis Banks, 1900),
Monog. Plecop., p. 58, male and female ; female genitalia, p. 305, figure 24;
male genital hook, p. 311, figure 7.
1942. Megarcys subtruncata Hanson, Amer. Midland Nat., 28:400, male and female;
female genitalia, p. 405, figure 17; male genitalia, p. 406, figure 24.
1943. Arcynopteryx signata subtruncata, Ricker, Stoneflies SW B.C., p. 111, nymph;
nymphal pattern and mouthparts, p. 115, figures 91 and 92.
Geographic range : Type locality: Paradise Valley, Mt. Rainier, Washington. Coast
and Cascade Mountains from southern British Columbia to Oregon. Creeks
and rivers. April-July. Common.
Arcynopteryx (Megarcys) watertoni Ricker (figure 22).
1952. Arcynopteryx (Megarcys) watertoni Ricker, Syst. Studies Plecop.,
p. 77,
male, female, and nymph ; male genitalia, p. 76, figure 37; placed in subgenus
Megarcys.
Geographic range: Type locality: Pass Creek, el. 4,800 ft., Waterton Lake National
Park, Alberta. Alberta, British Columbia, Montana. Creeks. June-August.
Common.
STONEFLIES OF THE PACIFIC NORTHWEST
63
Arcynopteryx (Megarcys) Yosemite (Needham and Claassen) (figure 22).
1925. Per lodes yosemite Needham and Claassen, Monog. Plecop., pp. 56-57; female
genitalia, p. 305, figure 20 ; male genitalia, p. 311, figure 8.
1952. Arcynopteryx (Megarcys) yosemite, Ricker, Syst. Studies Plecop.,
p. 78;
notes on identification of female.
Geographic range : Type locality : Mount Lyell at elevation 11,000 feet, California.
Cascade and Sierra Nevada Mountains at high elevation, Washington to
California. Creeks. July-August. Rare.
Arcynopteryx (Setvena) bradleyi (Smith) (figure 23).
1917. Protarcys bradleyi Smith, Trans. Amer. Ent. Soc. 43:470, description and
figures of male and female genitalia.
1925. Perlodes bradleyi, Needham and Claassen, Monog. Plecop., p. 53, description
of male and female; wings and female genitalia, p. 309, figures 4 and 5; male
genital hook, p. 311, figure 4.
1942. Perlodes tibialis, Frison, Bull. Ill. Nat. Hist. Sur. 72 :289, figure of female
genitalia (not tibialis Banks 1914).
1942. Protarcys bradleyi, Hanson, Amer. Midland Nat., 28:402, male and female ;
head and female genitalia, p. 405, figures 11 and 19; male genitalia, p. 406,
figure 26.
1952. Arcynopteryx bradleyi, Ricker, Syst. Studies Plecop., pp. 82-83; placed in new
subgenus Setvena.
Geographic range : Type locality : Lake Louise, Alberta. Rocky Mountains of Alberta, British Columbia, Idaho, and Montana. Creeks. June-August. Rare.
Arcynopteryx (Setvena) tibialis (Banks) (figure 23).
1914. Perlodes tibialis Banks, Proc. Acad. Sci. Phila. 66:608, description and figure
of male.
1917. Perlodes dolobrata Smith, Trans. Amer. Ent. Soc. 43:469, description and
figures of female.
1925. Perlodes tibialis, Needham and Claassen, Monog. Plecop., p. 54.
1925. Perlodes dolobrata, Needham and Claassen, ibid., p. 52, male and female ; p.
309, figures of wing and female genitalia.
1931. Perlodes tibialis, Claassen, Plecop. Nymphs, p. 44, nymph ; nymphal mouthparts, p. 131, figures 44-49.
1942. Perlodes dolobrata, Frison, Bull. Ill. Nat. Hist. Sur. 22:289, figures of male
genitalia.
1942. Protarcys tibialis, Hanson, Amer. Midland Nat. 28:402, male and female;
head and female genitalia, p. 405, figures 12 and 20; male genitalia, p. 406,
figure 27.
1952. Arcynopteryx tibialis, Ricker, Syst. Studies Plecop., p. 83; placed in new
subgenus Setvena.
Geographic range : Type locality : Olympic Mountains, Washington. Coast and Cascade Mountains of British Columbia to Oregon. Creeks. June-August. Rare.
Arcynopteryx (Skwala) curvata Hanson (figure 23).
1942. Arcynopteryx curvata Hanson, Amer. Midland Nat. 28:395, description of
male and female; female genitalia, p. 405, figure 13; male genitalia, p. 406,
figure 22.
1943. Arcynopteryx parallela curvata, Ricker, Stoneflies SW B.C., p. 114, description
of male and female; forewing, male and female genitalia, p. 115, figures 93-95,
97-98; placed in new subgenus Skwala.
Geographic range : Type locality : Wallace, Idaho. Southern British Columbia to
Oregon, Idaho and Montana. Creeks. February-May. Common.
Discussion: This species is ecologically separated from A. parallela inasmuch as it
frequents smaller, colder streams than does A. parallela. The length of the
dorsal hooks on the male 10th tergite can always be used to separate the two
STONEFLIES OF THE PACIFIC NORTHWEST
64
species. Some earlier workers (i.e., Needham and Claassen, 1925; Hanson,
1942) confused species in the subgenus Skwala with A. compacta McLachlan
(=Arcynopteryx americana [Klapalek]).
Arcynopteryx (Skwala) parallela (Frison) (figure 22).
1925. Per lodes americana, Needham and Claassen (not Klapalek 1912), Monog.
Plecop., p. 61, description of male and female; female genitalia, p. 305, figure
21 ; male genital hook, p. 311, figure 5.
1931. Per lodes americana, Claassen, Plecop. Nymphs, p. 44, incomplete description
of nymph.
1936. Hydroperla parallela Frison, Ann. Ent. Soc. Amer. 29:261, description and
figures of male.
1937. Hydroperla parallela Frison, Bull. Ill. Nat. Hist. Sur. 21:90; description of
female and figures of head and pronotum and female subgenital plate.
1942. Hydroperla parallela Frison, ibid., 22:298, description and figure of nymph.
1942. Arcynopteryx americana, Hanson, Amer. Midland Nat. 28:394, description of
male and female.
1943. Arcynopteryx parallela parallela, Ricker, Stoneflies SW B.C., p. 113, placed
in new subgenus Skwala.
Geographic range : Type locality: Corvallis, Oregon. Southern British Columbia to
California and Utah. Rivers. February-June. Common.
Arcynopteryx (Perlinodes) aurea Smith (figure 23).
1917. Arcynopteryx aurea Smith, Trans. Amer. Ent. Soc. 43:477-478, description
and figures of female genitalia and wings.
1917. Arcynopteryx vagans Smith, ibid., pp. 478-479, description and figures of male
genitalia and wings.
1925. Perlodes aurea, Needham and Claassen, Monog. Plecop., p. 62; female genitalia, p. 305, figure 23.
1925. Perlodes vagans, Needham and Claassen, ibid., pp. 66-67; male genitalia, p.
311, figures 2 and 9.
1942. Perlodes aurea, Frison, Bull. Ill. Nat. Hist. Sur. 22(2) :288; figures of head,
pronotum, sterna, and female genital plate.
1942. Perlinodes aurea, Hanson, Amer. Midland Nat., 28:401, description of male
and female ; p. 405, figure 10, head, and figure 18, female genitalia; male
genitalia, p. 406, figure 25.
1952. Arcynopteryx (Perlinodes) aurea Ricker, Syst. Studies Plecop., pp. 80-81,
description of nymph ; new name combination.
Geographic range : Type locality: California. Washington to California. Creeks,
small rivers. March-June. Rare.
Key to the Subgenera and Species of Pacific Northwest
Isogenus
Males (in part, females)
(Figure 24)
1.
Arms of the mesosternal Y-ridge meet the anterior corners of the furcal
pits
2
Arms of the mesosternal Y-ridge meet or approach only the posterior corners of the furcal pits
3
2 ( 1 ). Wings almost clear ; male lateral stylets short, with 2 or 3 terminal spinules
(Subgenus Osobenus)
yakintae
Wings dark brown; male lateral stylets long, smoothly rounded
(Subgenus Chernokrilus, in part)
misnomus
STONEFLIES OF THE PACIFIC NORTHWEST
65
3 (1). A median mesosternal ridge present running from the fork of the Y to the
transverse ridge ; submental gills several times as long as their greatest
diameter
(Subgenus Isogenoides)
4
Median mesosternal ridge absent from the fork of the Y to the transverse
ridge; submental gills, at most 2 or 3 times as long as their greatest diameter.
5
4 ( 3 ). Supra-anal process with a pair of acute lobes posteriorly ; subgenital plate
of female little produced, broadly truncate behind, with or without a small
5
elongatus
median notch
Supra-anal process of male without lobes posteriorly ; subgenital plate of fefrontalis colubrinus
male only a little produced, with a deep U-rounded notch
( 3 ). Lateral stylets absent from the male supra-anal process ; produced tip of the
anterior sclerotized band of the supra-anal body normally coiled within the
6
process
(Subgenus Kogotus)
Lateral stylets present ; tip of supra-anal process without a coiled structure 7
6 ( 5 ). Projecting tip of the paragenital plate slightly longer than the length of the
nonus
shortest cercal segment
Projecting tip of the paragenital plate less than half as long as the shortest
modestus
cercal segment
7 ( 5 ). Wings almost clear ; submental gills completely absent ; lateral stylets slender,
(Subgenus Cultus)
8
acute
Wings dark brown ; submental gills short but distinct ; lateral stylets rounded at
misnomus
(Subgenus Chernokrilus, in part)
the tip
8 ( 7 ). Hind head yellow centrally and with yellow lobes extending forward between
pilatus
the ocelli and between eyes and ocelli, 3 in all
9
Head pattern not as above
9 ( 8 ). Head mostly yellow, the only important dark marking being the bands which
join the anterior to the lateral ocelli ; median pronotal stripe, at its middle,
tostonus
about 1/5 of the width of the pronotum
Head mostly dark with restricted yellow patches ; median pronotal stripe at its
aestivalis
middle, about 1/10 of the width of the pronotum
Isogenus sorptus (Needham and Claassen) (figure 24).
1925. Perla sorpta Needham and Claassen, Monog. Plecop., p. 90, description of
female ; wing, p. 315, figure 4; female genitalia, p. 341, figure 10.
1952. Isogenus sorptus, Ricker, Syst. Studies Plecop., p. 131, head and female genitalia figured ; placed in genus Isogenus.
Geographic range : Type locality : Sequoia National Park, California. California and
Oregon. Rivers. May-June. Rare.
Discussion: This rare species is known only from two females, the holotype from
Sequoia National Park, California and a second specimen from Greasy Creek,
Corvallis, Oregon. The unknown male must be found to be certain of its
generic placement.
Isogenus (Chernokrilus) misnomus (Claassen) (figure 24).
1925. Perla obscura Needham and Claassen, Monog. Plecop., p. 92, description of
female ; female genitalia, p. 341, figure 15.
1936. Perla misnoma Claassen, Ann. Ent. Soc. Amer. 29 :622 ; new name.
1952. Isogenus misnomus, Ricker, Syst. Studies Plecop., p. 95; head, p. 94, figure
47; male and female genitalia, figures 48-51; placed in new subgenus Chernokrilus.
Geographic range : Type locality : Oregon Caves, Josephine County, Oregon. Western
Oregon. Creeks and rivers. May-July. Rare.
Discussion : Specimens of this subgenus are rarely collected, only a single male being known for each of the two described species. Additional male specimens
and the nymph would prove of great interest.
STONEFLIES OF THE PACIFIC NORTHWEST
66
Isogenus (Cultus) aestivalis (Needham and Claassen) (figure 24).
1925. Perla aestivalis Needham and Claassen, Monog. Plecop., p. 87, male and
female; wings, p. 319, figure 5; male and female genitalia, eggs, p. 327,
figures 7-10.
C
h
j
m
Figure 24. Head of Isogenus sorptus and terminalia of Isogenus. a, sorptus;
b, aestivalis; c, misnomus; d, f, pilatus; e, tostonus; g, h, colubrinus; i, j, elongatus; k, 1, nonus; m, yakimae. b, e, g, i, lateral view of male ; c, d, k, m, dorsal
view of male; f, h, j, 1, ventral view of female. (k, Claassen, 1937b; d, f, Frison,
1942b; g, h, i, j, Hanson, 1943b; m, Hoppe, 1938; 1, Needham and Claussen, 1925;
b, e, Ricker, 1943; a, c, Ricker, 1952).
STONEFLIES OF THE PACIFIC NORTHWEST
67
1931. Perla aestivalis (?), Claassen, Plecop. Nymphs, p. 53, nymph.
1943. Diploperla fraseri Ricker, Stoneflies SW B.C., p. 106, head and pronotum,
male and female genitalia, figures 84-87, 90.
1952. Isogenus aestivalis, Ricker, Syst. Studies Plecop., p. 96, above synonymy indicated and placed in new subgenus Cultus.
Geographic range: Type locality : Yellowstone National Park. British Columbia to
Utah, Colorado, and Wyoming. Rivers. May-July. Common.
Isogenus (Cultus) pilatus (Frison) (figure 24).
1942. Diploperla pilata Frison, Bull. Ill. Nat. Hist. Sur., 22:305 -307, description
and figures of male, female, nymph.
1952. Isogenus pilatus, Ricker, Syst. Studies Plecop., p. 97, placed in new subgenus
Cultus.
Geographic range: Type locality : Vedder Crossing, British Columbia. Coast and
Cascade Mountains from northern British Columbia to Oregon. Creeks and
rivers. April-June. Common.
Isogenus (Cultus) tostonus Ricker (figure 24).
1943. Diploperla aestivalis, Ricker, Stoneflies SW B.C., p. 107, figure 88, head and
pronotum; supra-anal process and lateral stylets of male, figure 89 (not
aestivalis Needham and Claassen 1925).
1952. Isogenus (Cultus) tostonus Ricker, Syst. Studies Plecop., pp. 97-98, description of male and female.
Geographic range: Type locality : Toston, Montana. British Columbia and Montana
to Wyoming and California. Creeks and rivers. May-July. Common.
Isogenus (Isogenoides) frontalis colubrinus Hagen (figure 24).
1874. Isogenus colubrinus Hagen, Bull. Geol. Surv. Terr., p. 576.
1918. Isogenus titusi Banks, Bull. Mus. Comp. Zool. 42:6.
1920. Isogenus incesta Banks, ibid., 64:318.
1925. Isogenus colubrinus, Needham and Claassen, Monog. Plecop., pp. 72-73.
1943. Isogenoides frontalis, Hanson, Amer. Midland Nat. 29:660, description of
male and female ; male genitalia, p. 667, figure 3 ; female genitalia, p. 668,
figures 17 and 18 (not frontalis Newman).
1952. Isogenus (Isogenoides) frontalis colubrinus, Ricker, Syst. Studies Plecop.,
p. 110; placed as a subspecies of frontalis.
Geographic range : Type locality : Snake River, Idaho. Alaska south to Oregon and
Utah, east in Mackenzie and northern Alberta to the MacKenzie River. Rivers.
March-May. Abundant.
Isogenus (Isogenoides) elongatus Hagen (figure 24).
1874. Isogenus elongatus Hagen, Bull. Geol. Surv. Terr., p. 576.
1925. Isogenus elongatus, Needham and Claassen, Monog., Plecop., p. 71, description of male and female; male supra-anal process, p. 311, figure 12, and female
genitalia, figure 17.
1942. Isogenoides elongatus, Hanson, Amer. Midland Nat., 29:660, description of
male and female; male genitalia, p. 667, figure 6; female genitalia, p. 668,
figures 11 and 12.
1952. Isogenus (Isogenoides) elongatus, Ricker, Syst. Studies Plecop., p. 108,
description of nymph and figures of nymphal mandible.
Geographic range : Type locality : Foothills of Colorado and Ogden, Utah. Rocky
Mountains region and adjacent plains from British Columbia and Alberta
south through Washington and Montana to Colorado. Rivers. May-July.
Common.
Discussion : This species occurs east of the Cascades and is sometimes associated
with I. colubrinus Hagen. Both species occur in the Columbia River at Vantage, Washington. The male of I. elongatus is brachypterous.
68
STONEFLIES OF THE PACIFIC NORTHWEST
Isogenus (Kogotus) modestus (Banks)
1908. Perla modesta Banks, Trans. Amer. Ent. Soc. 34:255.
1925. Perla modesta, Needham and Claassen, Monog. Plecop., p. 88, description of
male and female; p. 315, figure 1, wing ; p. 325, figures 16-19, male and female
genitalia.
1931. Perla expansa, Claassen, Plecop. Nymphs, p. 55 (not expansa Banks).
1942. Diploperla modesta, Frison, Bull. Ill. Nat. Hist. Sur. 22 :303-305, description
and figures of nymph.
1952. Isogenus modestus, Ricker, Syst. Studies Plecop., p. 116, placed in new subgenus Kogotus.
Geographic range: Type locality : Boulder, Colorado. Interior cordilleran ranges
from southern British Columbia to New Mexico. Creeks and rivers. May-July.
Common.
Discussion: The difference between this species and I. nonus (Needham and Claassen) is slight, and future collections may prove that the two are synonymous.
I. modestus occurs in the Rocky Mountains and I. nonus occurs in the Cascade and Coast Ranges.
Isogenus (Kogotus) nonus (Needham and Claassen (figure 24).
1925. Perla nona Needham and Claassen, Monog. Plecop., p. 86, description of
female; female genitalia, p. 325, figure 21.
1937. Perla nona, Claassen, Jour. Kans. Ent. Soc. 10:49, description of male; male
genitalia, p. 51, figures 5 and 14.
1952. Isogenus nonus, Ricker, Syst. Studies Plecop., pp. 116-117, placed in new subgenus Kogotus.
Geographic range : Type locality : Corvallis, Oregon. Southern British Columbia to
California. Creeks and rivers. April-July. Common.
Isogenus (Osobenus) yakimae (Hoppe) (figure 24).
1938. Perla yakimae Hoppe, Univ. Wash. Publ. Biol. 4:150, description of male;
male genitalia, p. 171, figures 1 and 2.
1952. Isogenus yakimae, Ricker, Syst. Studies Plecop., p. 118, description of male
and female, and placed in new subgenus Osobenus; male and female genitalia,
p. 119, figures 68-72.
1955. Isogenus (Osobenus) yakimae, Jewett, Wasmann Jour. Biol. 13(1) :148-149,
nymph.
Subfamily ISOPERLINAE
This is a fairly large subfamily, many species of which can be placed in
it only by the male genitalia. Even in the male the close relationship to members of the subfamily Isogeninae is seen in Calliperla and the recently described Rickera. Isoperla, the principal genus, contains a rich North American
fauna, 14 species of which have been taken in the Pacific Northwest. The
nymphs of several species have not been described so no key can be offered
for these.
Key to the Species of Pacific Northwest Isoperla
Males
(Figures 25, 26, 27)
1.
Crossveins present in the branches of the radial sector ; checkered pattern
of black on yellow on the pronotum
phalerata
Crossveins absent from the branches of the radial sector, pattern on pronotum variable
2
STONEFLIES OF THE PACIFIC NORTHWEST
69
C
d
e
1
I
Figure 25. Wings of Isoperla marmorata and terminalia of Calliper la and Iso-
perla. a, b, luctuosa; d, e, ebria; c, f, fusca; g, i, fulva; h, k, marmorata; j, 1,
gravitans. a, f, h, lateral view of male; e, dorsal view of male; b, c, d, i, 1, ventral view of female. (g, i, Claassen, 1937a; h, Jewett, 1954b; 1, Jewett, 1954a;
a-g, i, k, Needham and Claassen, 1925).
STONEFLIES OF THE PACIFIC NORTHWEST
70
2 (1). Tip of the 10th tergite with 2 small recurved processes ; 8th sternite without a lobe; head with a complete median dark stripe, darkest between the
ocelli; pronotum with broad median and lateral light stripes
trictura
Tip of 10th tergite without processes ; 8th sternite with a lobe (obsolescent
in ebria and gravitans); color of head and pronotum not as above
3
3 ( 2 ). Cerci about twice as long as the relaxed abdomen, the length of the 12th
segment 6 to 8 times its greatest width; 2 conspicuous patches of spinules
on the 9th tergite
longiseta
Cerci less than 1 times as long as the relaxed abdomen, the length of the
12th segment 3 to 5 times its greatest width ; usually without spinules on
the 9th tergite
4
4 ( 3 ). Lobe at tip of 8th sternite nearly square with subacute angles ; spinules
present on the male 9th tergite
rnorntona
Lobe on the 8th sternite broadly rounded behind; 9th tergite without spinules though with short stout hairs in patricia
5
5 ( 4 ). Pronotum with a checkered pattern of black on yellow ; subanal lobes flat,
recurved, chisel-shaped, bent outward near the tips
pinta
Pronotum striped or reticulately marked; subanal lobes not bent outward
close to the tips
6
6 ( 5 ). Ocellar area dark or with only a light spot, never wholly light
7
Ocellar area largely or wholly light in color
9
7 ( 6 ). Ocellar area almost or entirely dark and aedeagus with a sclerotized process the upper portion of which is furcate and turned abruptly downward
rainiera
Ocellar area usually with a light spot; aedeagus not as above
8
8 ( 7 ). Less than 10 mm. in length ; sclerotized aedeagal process furcate, each
upper arm bearing a tooth on its lower side towards the tip ; subanal lobes
round, short, pointed
fusca
10-11 mm. in length ; sclerotized aedeagal process furcate at tip, each arm
short and rounded; subanal lobes round, long, acutely bent upward, thin,
pointed
sordida
9 ( 6 ). Patches of short stout hairs on the posterior margin of the 9th tergite ;
often with a red cast to some of the abdominal segments
patricia
No patches of stout hairs on 9th tergite ; never with red tinge to abdominal
segments
10
10 ( 9 ). Lobe on 8th sternite obsolescent
11
Lobe on 8th sternite distinctive
12
11 (10). Pronotum with a broad, well defined median band of yellow on either side
of which is a broad blackish band
gravitans
Pronotum with a poorly defined median yellowish band on either side of
which are dark reticulate markings
ebria
12 (10). Entire anal area of hindwings at least faintly fumose ; subanal lobes cylindrical, robust, tapering to sharp tips
Inamorata
Anal area of hindwings not fumose; subanal lobes not as above
13
13 (12). Head pattern interrupted at the transverse occipital suture; aedeagus without a slender sharp process
fulva
Head pattern if any, continuous across the occipital suture; aedeagus with
a slender sharp process, forked at the base
petersoni
STONEFLIES OF THE PACIFIC NORTHWEST
71
Key to the Species of Pacific Northwest Isoperla
Females (rainiera undescribed)
(Figures 25, 26, 27)
1.
2
Crossveins present in the branches of the radial sector ; checkered pattern of
phalerata
black on yellow on the pronotum
Crossveins absent from the branches of the radial sector ; pattern on pro2
notum variable
( 1 ) Eighth sternite not produced except for a small median process; head with
a complete median dark stripe, darkest between the ocelli; pronotum with
trictura
a broad median and lateral light stripes
3
Eighth sternite not as above; color of head and pronotum not as above
3 ( 2 ). Cerci about twice as long as the relaxed abdomen, the length of the 12th
segment 6 to 8 times its greatest width; subgenital plate somewhat prolongiseta
duced and rounded, truncate or slightly excavated
Cerci less than 1 times as long as the relaxed abdomen, the length of the
4
12th segment 3 to 5 times its greatest width; subgenital plates variable
mormona
4 ( 3 ) Subgenital plate little produced; a small yellow species
5
Subgenital plates variable; medium to large species
5
( 4 ). Pronotum with a checkered pattern of black on yellow; subgenital plate
moderately produced, slightly excavated at the middle
Pronotum striped or reticulately marked; subgenital plates variable
6 ( 5 ). Ocellar area with only a light spot, never wholly light
Ocellar area largely or wholly light in color
7 ( 6 ). Less than 11 mm. in body length
pinta
6
7
8
fusca
sordida
Eleven to 12 mm. in body length
8 ( 6 ). Subgenital plate with a wide, deep excavation; often with red cast to some
Patricia
of the abdominal segments
Subgenital plate without a wide, deep excavation; never with a red tinge
9
to abdominal segments
9 ( 8 ). Subgenital plate at least as long as the 7th sternite, its sides parallel or
nearly so at the base
10
11
Subgenital plate shorter than the 7th sternite, its sides turned inward
10 ( 9 ). Pronotum with a broad, well defined median band of yellow on either side
gravitans
of which is a broad blackish band
Pronotum with a poorly defined median yellowish band on either side of
ebria
which are dark reticulate markings
11
( 9 ). Entire anal area of hindwings at least faintly fumose; subgenital plate
marmorata
truncate or slightly produced
Anal area of hindwings not fumose; subgenital plate broadly rounded ..... 12
12 (11). Subgenital plate thickened and rather suddenly bent downward near the
fulva
tip; head pattern interrupted at the transverse occipital suture
Subgenital plate flat, thickened and slightly emarginate at the tip, but not
sharply bent downward; head pattern if any, continuous across the occipetersoni
pital suture
Calliperla luctuosa (Banks) (figure 25).
1906. Perla luctuosa Banks, Can. Ent. 38:336, description of female.
1925. Perla luctuosa, Needham and Claassen, Monog. Plecop., p. 97, description of
male and female; wings, p. 315, figure 8; male and female genitalia, p. 327,
figures 16-19.
Geographic range: Type locality : San Francisco, California. Western California and
Oregon. Creeks, small rivers. May-July. Common.
72
STONEFLIES OF THE PACIFIC NORTHWEST
Discussion: This showy, monotypic species emerging rather late in the spring occurs
as far north as the Necanicum River, Clatsop County, Oregon. Discovery of
the nymph would aid in understanding better its relationship to other genera
in the Isoperlinae.
Isoperla ebria (Hagen) (figure 25).
1875. Perla ebria Hagen, Bull. Geol. Surv. Terr., p. 577.
1925. Clioperla ebria, Needham and Claassen, Monog. Plecop., pp. 141-142 ; male
and female genitalia, p. 351, figures 1-3.
1931. Clioperla ebria, Claassen, Plecop. Nymphs, p. 71, description of nymph.
1943. Isoperla ebria, Ricker, Stoneflies SW B.C., pp. 121-122, description of nymph;
nymph, nymphal mouthparts, and female subgenital plate, p. 123, figures
107-110.
Geographic range: Type locality : Colorado. British Columbia to Colorado and California. Creeks and rivers. May-July. Common.
Isoperla fulva Claassen (figure 25).
1937. Isoperla fulva Claassen, Can. Ent. 69:80, description of male and female.
1938. Isoperla chrysannula Hoppe, Univ. Wash. Publ. Biol. 4:156; male genitalia,
p. 173, figures 13-14.
1938. Isoperla cascadensis Hoppe, ibid., p. 158, description of male and female; male
and female genitalia, p. 173, figures 17-19.
1942. Isoperla fulva, Frison, Bull. Ill. Nat. Hist. Sur. 22(2) :337, synonymy indicated.
Geographic range: Type locality : Logan River, Utah, British Columbia to California and Utah. Creeks and rivers. March-June. Common.
Isoperla fusca Needham and Claassen (figure 25).
1925. Isoperla fusca Needham and Claassen, Monog. Plecop., pp. 146-147, description of male and female; male and female genitalia, p. 343, figures 4-6.
1942. Isoperla fusca, Frison, Bull. Ill. Nat. Hist. Sur. 22(2) :317-318, description
of male and female, and nymph; figure 92, nymph; figure 93, male and female
genitalia and nymphal mouthparts.
Geographic range: Type locality : Waterton Lakes, Alberta. Alberta and British
Columbia south to Oregon. Creeks. May-July. Common.
Isoperla gravitans (Needham and Claassen) (figure 25).
1925. Clioperla gravitans Needham and Claassen, Monog. Plecop., pp. 138-139, description of male; wings, p. 313, figure 6; male genitalia, p. 341, figures 7-8.
1954. Isoperla gravitans, Jewett, Jour. Fish. Res. Bd. Can. 11(5) :548; description
and figure of female genitalia.
Geographic range: Type locality : Olympia, Washington. Western Washington and
Oregon. Creeks, springs. March-May. Rare.
Isoperla longiseta Banks (figure 26).
1906. Isoperla longiseta Banks, Can. Ent. 58:337, female.
1925. Isoperla longiseta, Needham and Claassen, Monog. Plecop., p. 156, description
of male and female; male and female genitalia, p. 342, figures 15-17.
Geographic range: Type locality : Onaga, Kansas. Midwest west to British Columbia. Creeks and rivers. June. Rare in Pacific Northwest.
Isoperla marmorata (Needham and Claassen) (figure 25).
1925. Clioperla marmorata Needham and Claassen, Monog. Plecop., pp. 142-143, description of female; wings, p. 317, figure 6; female genitalia, p. 341, figure 11.
1954. Isoperla marmorata, Jewett, Pan-Pac. Ent. 30(3) :178-179, description and
figure of male genitalia.
Geographic range: Type locality : Nevada. Oregon to California and Nevada. Creeks.
April-June. Common.
STONEFLIES OF THE PACIFIC NORTHWEST
73
C
a
i
k
1
1.
Figure 26. Wings of Isoperla phalerata and terminalia of Isoperla. a, c, mormona; b, longiseta; d, e, patricia; f, g, pinta; h, i, phalerata; j, 1, sordida; k,
rainiera. a, b, d, f,
i,
j, dorsal view of male; k, aedeagus of male; c, e, g, 1,
ventral view of female. (f, g, Frison, 1937; d, e, Frison, 1942b; k, Jewett, 1954a;
i, Jewett, 1954b; a, c, j, 1, Needham and Claassen, 1925; b, Ricker, 1943; h, Ricker, 1952).
74
STONEFLIES OF THE PACIFIC NORTHWEST
Discussion : I. marmorata can be distinguished from similar species in the genus by
the fumose anal area of the hindwings. if the entire wings are slightly smoky
these anal areas will be darkest. As with other members of this genus the head
pattern is useful as a specific characteristic, but the pattern does vary and at
times is very similar to that of I. fulva Claassen.
Isoperla mormona Banks (figure 26).
1920. Isoperla mormona Banks, Harvard Coll. Mus. Comp. Zool. Bull., 64:322, description of female.
1925. Isoperla mormona, Needham and Claassen, Monog. Plecop., pp. 153-154, description of male and female; male and female genitalia, p. 345, figures 1-3.
1938. Isoperla insipida Hoppe, Univ. Wash. Publ. Biol. 4:157, description of male
and female.
Geographic range: Type locality : Vinyard, Utah. British Columbia to California
and Wyoming and Arizona. Creeks and rivers. May-July. Abundant.
Isoperla patricia Frison (figure 26).
1942. Isoperla Patricia Frison, Bull. Ill. Nat. Hist. Sur. 22(2) :313-315, description
and figures of male and female and nymph; figure 87, male and female genitalia, nymphal pattern, and mouthparts.
Geographic range: Type locality : Spearfish, South Dakota. British Columbia to
California and South Dakota to Colorado. Creeks and rivers. May to July.
Abundant.
Isoperla petersoni Needham and Christenson (figure 27).
1927. Isoperla petersoni Needham and Christenson, Utah Ag. Exp. Sta. Bull. 201,
p. 19, adult and nymph, figures 24 and 25.
1929. Isoperla fontium Neave, Contr. Can. Biol. Fish. 4:161, male and female; male
and female genitalia, figures 3-5.
1937. Isoperla petersoni, Claassen, Can. Ent. 69:81-82, male and female genitalia,
p. 78, figures 11, 13, 14.
1954. Isoperla petersoni, Ricker, Proc. Ent. Soc. B.C. 51:39, above synonymy indicated.
Geographic range : Type locality : Peterson's Spring, Utah. Alberta and British Columbia south to Utah. Creeks, springs. July-September. Rare.
Isoperla phalerata (Needham) (figure 26).
1917. Dictyogenus (?) phaleratus Needham, in Smith, Trans. Amer. Ent. Soc.
43 :485.
1925. Perla phalerata, Needham and Claassen, Monog. Plecop., p. 91, description
of female; female genitalia and egg, p. 325, figures 9-10.
1952. Isogenus phaleratus, Ricker, Syst. Studies Plecop., p. 131; head, wings, female genitalia, p. 130, figures 82-85.
1954. Isoperla phalerata, Jewett, Jour. Fish. Res. Bd. Can. 11(5) :548-549; placed in
Isoperla, description and figure of male.
Geographic range: Type locality : Colorado. Colorado and Wyoming ; Oregon. Creeks
and rivers. May-June. Rare.
Isoperla pinta Frison (figure 26).
1937. Isoperla pinta Frison, Bull. Ill. Nat. Hist. Sur. 21 :92-93, description of male,
female, and nymph; male and female genitalia and nymph, figures 81 and 82.
Geographic range: Type locality : Curry County, Oregon. British Columbia to California. Creeks and rivers. March-May. Abundant.
Isoperla rainiera Jewett (figure 26).
1954. Isoperla rainiera Jewett, Jour. Fish. Res. Bd. Can., 11(5) :549, description and
figure of male.
STONEFLIES OF THE PACIFIC NORTHWEST
75
Geographic range: Type locality : Mount Rainier, Washington. Known only from
Mt. Rainier, Washington and Mt. Hood, Oregon. Creeks. July-August. Rare.
Isoperla sordida (Banks) (figure 26).
1906. Perla sordida Banks, Can. Ent. 38:338, description of female.
1925. Isoperla sordida, Needham and Claassen, Monog. Plecop., pp. 152-153, description of male and female; male and female genitalia, p. 345, figures 13-15.
Geographic range : Type locality: Los Angeles County, California. Washington to
California. Creeks and rivers. June-September. Common.
Discussion: Isoperla sordida is usually a late summer or autumn species in the Pacific Northwest. In addition to the key characters, the yellow 9th and 10th
segments of the male contrast sharply with the other abdominal segments
which are generally dark brown.
Isoperla trictura (Hoppe) (figure 27).
1938. Perla trictura Hoppe, Univ. Wash. Publ. Biol. 4:151, description of male and
female; male and female genitalia, pl. 17, figures 3 and 4.
1942. Isoperla trictura, Frison, Bull. Ill. Nat. Hist. Sur. 22(2) :336, figure 114, new
illustration of male and female genitalia.
Geographic range: Type locality: Cedar River (Maple Valley), Washington. Washington to California. Creeks. April-June. Common.
Rickera venusta Jewett (figure 27).
1954. Rickera venusta Jewett, Pan-Pac. Ent. 30(3) :176, description and figures of
male and female ; placed in new genus Rickera.
1955. Rickera venusta Jewett, Wasmann Jour. Biol. 13(1) :149-150, nymph.
Geographic range: Type locality: Rogue River at Foster Creek, Jackson County,
Oregon. Cascade Mountains and Sierra Nevada of Oregon and California.
Creeks and rivers. May-July. Rare.
e
Figure 27. Terminalia of Isoperla and Rickera. a, b, trictura; c, petersoni;
d, e, venusta. a, c, d, lateral view of male; b, e, ventral view of female. (c, Claassen, 1937a; a, b, Frison, 1942b; d, e, Jewett, 1954b).
76
STONEFLIES OF THE PACIFIC NORTHWEST
Subfamily PERLODINAE
Only one species of this typically Eurasian subfamily is known to occur
in the region covered by this treatment. The male is readily placed by the key
on page 20, the female, by the illustration of the subgenital plate.
Diura (Dolkrila) knowltoni (Frison) (figure 28).
1937. Dictyopterygella knowltoni Frison, Bull. Ill. Nat. Hist. Sur. 21 :89, description
of male and figures of color pattern, forewing, and male genitalia.
1942. Dictyopterygella knowltoni Frison, ibid., 22 :299, description of female and
nymph; figures of female genitalia, nymphal color pattern, and nymphal
mouthparts.
1952. Diura knowitoni, Ricker, Syst. Studies Plecop., p. 138; placed in genus Diura
and new subgenus Dolkrila.
Geographic range : Type locality : Logan, Utah. Vancouver Island to Oregon and
from Yukon south to Utah. Creeks and rivers. April-June. Common.
Figure 28. Terminalia of
Diura knowltoni. a, dorsal
view of male; b, ventral
view of female. (a, Frison,
1937; b, Frison, 1942b).
Family CHLOROPERLIDAE
Subfamily PARAPERLINAE
This subfamily contains three monotypic genera which seem to link the
Chloroperlidae with the Isoperlinae. These are readily placed by employing
the key on page 20, and by reference to the figures on the plates.
Kathroperla perdita Banks (figure 29).
1920. Kathroperla perdita Banks, Bull. Mus. Comp. Zool. 64:315.
1925. Kathroperla perdita, Needham and Claassen, Monog. Plecop., pp. 132-133, de-
scription of male and female; wings, p. 321, figure 6; male and female genitalia, p. 337, figures 7 and 8.
1934. Kathroperla perdita, Neave, Can. Ent. 66:2, description of nymph.
Geographic range: Type locality : Kaslo, British Columbia. Alaska to California.
Creeks and small rivers. April-June. Common.
Paraperla frontalis (Banks) (figure 29).
1902. Perlinella frontalis Banks, Can. Ent. 34:123.
1925. Paraperla frontalis, Needham and Claassen, Monog. Plecop., pp. 130-131, description of male and female; wings, p. 321, figure 8; male and female genitalia, p. 337, figures 4-6.
STONEFLIES OF THE PACIFIC NORTHWEST
77
1931. Paraperla frontalis, Claassen, Plecop., Nympsh, p. 65, description of nymph ;
mouthparts, pl. 7, figures 100-105; wing pads, pl. 10, figures 167-168; body of
nymph, pl. 18, figure 193.
Geographic range: Type locality : New Mexico. British Columbia to New Mexico
and California. Creeks, small rivers. April-June. Common.
Utaperla sopladora Ricker (figure 29).
1952. Utaperla sopladora Ricker, Syst. Studies Plecop., pp. 174-176, description of
male and female; male and female genitalia and wings, p. 175, figures 125-130.
Geographic range : Type locality : Puffers Lake, Utah. Yukon to Idaho, Montana,
and Utah. Creeks. May-July. Rare.
d
Figure 29. Terminalia of Paraperlinae. a, b, Kathroperla perdita; c, d, Paraperla frontalis; e, f, Utaperla sopladora. a, c, lateral view of male; e, dorsal
view of male; b, d, f, ventral view of female. (a-d, Needham and Claassen, 1925;
e, f, Ricker, 1952).
STONEFLIES OF THE PACIFIC NORTHWEST
78
Subfamily CHLOROPERLINAE
Two genera of this subfamily occur in the Pacific Northwest, Hastaperla
and Alloperla. They are easily separated because Hastaperla lacks an anal
area in the hindwings. Alloperla has been divided into a number of subgenera
which cannot always be separated except in the male. Species of the subgenus
Alloperla are usually green in life but one species, A. delicata Frison, may be
yellow. The nymphs cannot be separated, except those of mature males with
visible genitalia. The females of several species cannot be separated satisfactorily ; figure 32 illustrates the subgenital plates of a few.
Key to the Subgenera and Species of Pacific Northwest Alloperla
Males
(Figures 30, 31)
Basal segment of the cerci greatly elongated, deeply concave inward, with
a sharp spine inside near the base and with 4 blunt knobs on the inside near
the tip; 9th tergite with its hind border produced backward, from which
comes a stout forward-pointing decurved hook
(Subgenus Neaviperla)
forcipata
Cerci normal ; 9th tergite without a median forward-projecting hook
2
2 ( 1 ). A finger-like process pointing inward from the basal segment of each cercus ; supra-anal body a membranous lobe with a very small hairy process
at its tip
(Subgenus Suwallia)
3
No process at the base of the cerci ; supra-anal body elongate, its terminal
process usually larger
5
3 (2 ). Color lemon to whitish-yellow ; aedeagus without dark, sclerotized appen1.
dages
4
Color yellowish-brown ; aedeagus with a curved, slender median and 2
broad, lateral, dark, sclerotized appendages
autumna
4 ( 3 ). Aedeagus with 3 ventral sclerotized patches of tiny spinules
pallidula
Aedeagus with a single, V-shaped patch of sclerotized spinules
lineosa
5 (2). Color usually green (sometimes yellow in delicata) in life; no dark abdominal stripe; 9th tergite without a process .... (Subgenus Alloperla) ....
Color mostly yellow in life; a dark dorsal abdominal stripe present ; usually
a process on the 9th tergite
6 ( 5 ). Process at the tip of the supra-anal body longer than wide
Process at the tip of the supra-anal body wider than long or little longer
6
9
7
than broad
8
7 ( 6 ). Supra-anal body halberd-shaped, the tip with three points
medveda
Supra-anal process dumbbell-shaped, rounded in front and behind
severa
8 ( 6 ). Process ellipsoid, broader than long, armed with very short, blunt, ventrallypointing spines at its tip
serrata
Process short, its anterior corners produced into acute angles .......... delicata
9 ( 5 ). Body of supra-anal apparatus lying in a deep groove of the 10th tergite
and attached to its sides, bearing at its posterior end a terminal portion
which is well marked off from the rest of the apparatus
(Subgenus Sweltsa)
10
Body of the supra-anal apparatus obscure, short, and lying along the surface
of and fused with the 10th tergite, usually in a slight depression but never
in a deep groove
(Subgenus Triznaka)
20
STONEFLIES OF THE PACIFIC NORTHWEST
79
Figure 30. Male terminalia of Alloperla. a, delicata; b, medvena; c, serrata;
d, severa; e, forcipata; f, pallidula; g, borealis; h, coloradensis; i, exquisita; j,
fidelis. a-f, i, j, dorsal view; g, h, lateral view. (a, d, f, i, Frison, 1935b; e, Neave,
1929; c, g, h, j, Needham and Claassen, 1925; b, Ricker, 1952).
STONEFLIES OF THE PACIFIC NORTHWEST
80
SUPRAANAL
OCES
a
f
i
Figure 31. Head of Alloperla pintada and male terminalia of Alloperla. a, fraterna; b, lamba; c, occidens; d, oregonensis; e, pacifica; f, diversa; g, h, pintada;
i, revelstoki. a, d, f, dorsal view; b, c, e, h, lateral view. (a, d, f, Frison, 1935b;
c, Frison, 1937; i, Jewett, 1955; b, e, Needham and Claassen, 1925, g, h, Ricker,
1952).
STONEFLIES OF THE PACIFIC NORTHWEST
10 ( 9 ). A definite elevated transverse and usually notched process near the anterior border of the 9th tergite
No process on the 9th tergite
81
12
11
11 (10). Margins of the pronotum only faintly darkened; no dark U-marks on mesoand metanota ; supra-anal process small, elongate, rounded at the tip,
fraterna
somewhat constricted in the middle
Margins of pronotum and U-marks on meso- and metanota black; supraoccidens
anal process long, nearly cylindrical, blunt at the tip
Pacifica
12 (10). A bifurcate transverse process on the 8th tergite
13
No process on the 8th tergite
13 (12). Disk of the pronotum clear yellow ; supra-anal process terete, slender,
exquisita
bluntly pointed
Disk of the pronotum with black reticulate markings, sometimes absent in
14
fidelis; supra-anal process variable
14 (13). Supra-anal process slender, somewhat expanded toward the tip in dorsal
view
Supra-anal process thick, broadly flattened in dorsal view
15
17
15 (14). Supra-anal process about 1.7 times as broad near the tip as it is near
fidelis
the base
16
Supra-anal process less broad near the tip than it is closer to the base
revelstoki
16 (15). Found at high elevations in Hudsonian or Canadian life zones
borealis
Found at lower elevations in Transition life zone
oregonensis
17 (14). Supra-anal process concave above, its tip broadly rounded
18
Supra-anal process flattened, with a short upturned spine at the tip
18 (17). Supra-anal process with a slightly upturned spine at the tip ; a bifurcate,
darkly sclerotized, leaf-like appendage arising from the base of the aedeagus
19
Supra-anal process with a short upturned hook at the tip; no leaf-like apcoloradensis
pendage arising from the aedeagus
lamba
19 (17). Median carina of supra-anal process high
albertensis
Median carina of supra-anal process low
20 ( 9 ). Head and pronotum with conspicuous median markings of black on yellow ;
21
a small posterior median lobe on the 7th sternite
Head unmarked except for the ocellar rings ; pronotum with dusky lateral
diversa
margins, otherwise yellow ; no lobe on the 7th sternite
21 (20). Anterior mark on the head as long as broad, often produced in the midline
back to the median ocellus ; median pronotal mark broadly T-shaped, little
produced laterally rearward ; pronotal rugosities not pigmented or very
signata
(Rocky Mountains region)
lightly so
Anterior mark of the head about twice as wide as long, not reaching to
the median ocellus ; median pronotal mark narrow, I-shaped, much produced laterally both at the front and at the rear ; pronotal rugosities rather
pintada
heavily pigmented, at least near the midline
Key to the Subgenera and Species of Pacific Northwest Alloperla
Females
(Figure 32)
1.
2
Abdomen with a black dorsal stripe
Abdomen without a black dorsal stripe
delicate, medveda, serrata, and severa
(Subgenus Alloperla)
2 (1). Pronotum without dark reticulate markings
Pronotum with dark reticulate markings
3
12
82
STONEFLIES OF THE PACIFIC NORTHWEST
3 (2 ). Sides of pronotal disk dusky, not with striking black margins
4
Sides, top, and bottom of pronotal disk strongly margined in black
9
4 ( 3 ). Sides of disk with a dusky band that occupies about a fourth of each side
of the disk
fraterna
Sides of disk with a narrow darkened band
5
5 ( 4 ). Disk margined on sides by a dark, narrow band; subgenital plate broadly
rounded and about equal in length to 8th sternite
6
Disk margined on sides by a fine line ; subgenital plate truncate or slightly
emarginate and longer than the 8th sternite
7
e
Figure 32. Female terminalia of Alloperla and male terminalia of Hastaperla
chilnualna. a, severa; b, forcipata; c, pallidula; d, borealis; e, coloradensis; f,
exquisita; g, pintada; h, chilnualna. (a, c, Frison, 1935; f, Frison, 1937; d, e,
Needham and Claassen, 1925; b, Ricker, 1943; g, h, Ricker, 1952).
STONEFLIES OF THE PACIFIC NORTHWEST
83
6 ( 5 ). First segment of cerci at least 3 times as long as the second, slightly concave on inner margin
forcipata
First segment of cerci little longer than the second, not cancave on inner
margin
diversa
7 ( 5 ). Subgenital plate emarginate
lineosa
Subgenital plate rounded or truncate
8
8 ( 7 ). Body generally yellow
pallidula
Body generally brownish yellow
autumna
9 ( 3 ). Subgenital plate notched
10
Subgenital plate not notched
11
10 ( 9 ). Notch in subgenital plate square or nearly so
borealis and revelstoki
Notch in subgenital plate bilobed
fidelis
11 ( 9 ). Subgenital plate markedly thickened in lateral view
Pacifica
Subgenital plate not markedly thickened in lateral view
exquisite and occidens
12 (2 ). Subgenital plate notched
13
Subgenital plate not notched
14
13 (12). Notch in subgenital plate square or nearly so
borealis and revelstoki
Notch in subgenital plate bilobed
fidelis
14 (12). Head with a striking, large, black spot occupying the ocellar triangle .... pintada
Head without a striking, large, black spot in ocellar area
15
15 (14). Head pattern in a continuous dark area ; subgenital plate narrowly
rounded
oregonensis
Head pattern broken into several reticulate markings ; subgenital plate almost truncate
albertensis, coloradensis, and lamba
Alloperla (Alloperla) delicata Frison (figure 30).
1935. Alloperla delicata Frison, Trans. Amer. Ent. Soc. 61 :334, description of male ;
head and prothorax, pl. 11, figure 6 ; wings, pl. 11, figure 1 ; dorsum of abdomen, pl. 13, figure 23 ; male genitalia, pl. 13, figures 23, 24, and 29.
1954. Alloperla (Alloperla) delicata, Jewett, Jour. Fish. Res. Bd. Can. 11(5) :549,
description and figure of female genitalia.
Geographic range : Type locality : Oak Creek, Corvallis, Oregon. Vancouver Island
south to Oregon. Creeks, small rivers. May-July. Abundant.
Alloperla (Alloperla) medveda Ricker (figure 30).
1952. Alloperla (Alloperla) medveda Ricker, Syst. Studies Plecop., pp. 177-178,
description of male and possible female ; male genitalia, p. 179, figure 137.
Geographic range : Type locality : Bear Tooth Creek, elevation 9,500 feet, Bear
Tooth Mountains, Montana. Yukon and Alberta to Idaho and Wyoming.
Creeks. May-July. Rare.
Alloperla (Alloperla) serrata Needham and Claassen (figure 30).
1925. Alloperla serrata Needham and Claassen, Monog. Plecop., pp. 124-125, description of male and female ; male and female genitalia, p. 331, figures 12
and 13.
Geographic range: Type locality : Moraine Lake, Alberta. Alberta, British Columbia, Idaho. Creeks. May-July. Rare.
Alloperla (Alloperla) severa (Hagen) (figure 30).
1861. Perla severa Hagen, Syn. Neur. North Amer., p. 30.
1935. Alloperla elevata Frison, Trans. Amer. Ent. Soc., 61 :335-336, description of
male and female ; male genitalia, pl. 12, figures 11 and 12, pl. 13, figures 27
and 28; female genitalia, pl. 14, figure 41.
1952. Alloperla (Alloperla) thalia Ricker, Syst. Studies Plecop., p. 178, description
of male and female ; male and female genitalia, p. 179, figures 131 and 134.
84
STONEFLIES OF THE PACIFIC NORTHWEST
1954. Alloperla (Alloperla) severa, Ricker, Trans. Ent. Soc. B.C., 51, 39; above
synonymy indicated.
Geographic range : Type locality : Alaska. Alaska to Oregon and Montana. Creeks.
May-June. Common.
Alloperla (Neaviperla) forcipata Neave (figure 30).
1929. Alloperla forcipata Neave, Contri. Can. Biol. and Fish. N.S. 4(13) :160; description and figure of male.
1943. Alloperla forcipata, Ricker, Stoneflies SW B.C., pp. 141-142, description of
male and female ; placed in new subgenus Neaviperla.
Geographic range : Type locality : Lake Edith, Alberta. Alaska and Alberta south to
Washington. Creeks and rivers. July-September. Common.
Alloperla (Suwallia) autumna Hoppe
1938. Alloperla autumna Hoppe, Univ. Wash. Publ. Biol. 4 :152-153; description and
figures of male and female.
Geographic range : Type locality : North Fork of Snoqualmie River, North Bend,
Washington. British Columbia and Montana south to Oregon. Creeks, small
rivers. August-October. Common.
Alloperla (Suwallia) lineosa Banks
1918. Alloperla lineosa Banks, Bull. Mus. Comp. Zool. 62 :7.
1925. Alloperla lineosa, Needham and Claassen, Monog. Plecop., p. 123, description
of male and female ; male and female genitalia, p. 331, figures 10 and 11
(figure 10, male, is incorrectly identified).
1955. Alloperla (Suwallia) lineosa, Jewett, Wasmann Jour. Biol. 13(1) :151-152,
male and female.
Geographic range : Type locality : Grant, Colorado. Montana to Colorado; Oregon
and Washington. Creeks. June-August. Common.
Alloperla (Suwallia) pallidula (Banks) (figure 30).
1904. Chloroperla pallidula Banks, Trans. Amer. Ent. Soc. 30:99; description of
female.
1925. Alloperla pallidula, Needham and Claassen, Monog. Plecop., pp. 108-109, de-
scription of male and female; male and female genitalia, p. 335, figures 12
and 13.
1935. Alloperla dubia Frison, Trans. Amer. Ent. Soc. 61:338-339, description of
male and female ; male genitalia, pl. 11, figures 8 and 9, pl. 14, figure 33; female genitalia, pl. 14, figure 37.
Geographic range : Type locality : New Mexico. Alaska to California and Alberta
to Wyoming. Creeks and rivers. May-September. Abundant.
Discussion : A. pallidula is the commonest of the three described western North
American species of the subgenus Suwallia. A. autumna Hoppe emerges in
the autumn and is darkish ; the male possesses distinctive penial appendages.
The male of A. lineosa Banks is very similar to that of A. pallidula except
for the structures of the aedeagus. A patch of fine, sclerotized hairs in the
form of a V is found on the underside of the aedeagus of A. lineosa. Three
oval patches of extremely fine spinules occur on the underside of the aedeagus
of A. pallidula; dorsally the terminal patches connect to form a single patch.
The end of the subgenital plate in the female of A. lineosa is concave, not
truncate or convex as in A. pallidula and A. autumna.
Alloperla (Sweltsa) albertensis Needham and Claassen
1925. Alloperla albertensis Needham and Claassen, Monog. Plecop., p. 116, description of male and female; male and female genitalia, p. 335, figures 6 and 7.
Geographic range : Type locality : Waterton Lakes, Alberta. Alberta, Montana, and
Idaho. Creeks. July. Rare.
STONEFLIES OF THE PACIFIC NORTHWEST
85
Alloperla (Sweltsa) borealis (Banks) (figure 30).
1895. Chloroperla borealis Banks, Trans. Amer. Ent. Soc. 22 :313, description of
male and female.
1925. Alloperla borealis, Needham and Claassen, Monog. Plecop., p. 118, description
of male and female; wing, p. 319, figure 1 ; male and female genitalia, p. 333,
figures 1-3.
1931. Alloperla borealis, Claassen, Plecop. Nymphs, p. 60, description of nymph;
pl. 6, figures 89-93, nymphal mouthparts; pl. 17, figure 192, nymph.
Geographic range : Type locality : Olympia, Washington. Alaska to Colorado and
California. Creeks. April-July. Common.
Alloperla (Sweltsa) coloradensis (Banks) (figure 30).
1898. Chloroperla coloradensis Banks, Trans. Amer. Ent. Soc. 25:199.
1925. Alloperla coloradensis, Needham and Claassen, Monog. Plecop., pp. 113-114,
description of male and female; male and female genitalia, p. 335, figures
4 and 5.
1931. Alloperla coloradensis, Claassen, Plecop. Nymphs, pp. 60-61, description of
nymph; nymphal mouthparts, pl. 6, figures 83-88.
Geographic range : Type locality: Colorado. British Columbia to California ; Montana
to Colorado. Creeks. April-June. Common.
Alloperla (Sweltsa) exquisita Frison (figure 30).
1935. Alloperla exquisita Frison, Trans. Amer. Ent. Soc. 61:337-338, description of
male; abdomen, pl. 12, figure 21; male genitalia, pl. 12, figure 17, pl. 13, figure 30.
1937. Alloperla exquisita Frison, Bull. Ill. Nat. Hist. Sur. 21(3) :96, description and
figure of female.
Geographic range: Type locality : Mount Hood National Forest, near Welches,
Oregon. British Columbia to Oregon. Creeks. May-July. Common.
Alloperla (Sweltsa) fidelis Banks (figure 30).
1920. Alloperla fidelis Banks, Bull. Mus. Comp. Zool. 64:323, description of male
and female.
1925. Alloperla fidelis, Needham and Claassen, Monog. Plecop., pp. 119-120, description of male and female; male and female genitalia, p. 331, figures 8-10.
1942. Alloperla fidelis, Frison, Bull. Ill. Nat. Hist. Sur. 22 (2) :346, description and
figures of male and female with brachypterous wings.
Geographic range: Type locality : Great Alpine Creek, Tahoe, California. Alaska to
California ; Idaho to Wyoming. Creeks and rivers. May-July. Abundant.
Alloperla (Sweltsa) fraterna Frison (figure 31).
1935. Alloperla fraterna Frison, Trans. Amer. Ent. Soc. 61: 334-335, description of
male and female; prothorax, pl. 11, figure 4; abdomen, pl. 12, figure 19; male
genitalia, pl. 12, figures 15 and 19 ; female genitalia, pl. 14, figure 39.
Geographic range : Type locality: Oak Creek, Corvallis, Oregon. British Columbia to
California. Creeks. May-July. Common.
Alloperla (Sweltsa) laznba Needham and Claassen (figure 31).
1925. Alloperla lamba Needham and Claassen, Monog. Plecop., p. 115, description
of male and female; male and female genitalia, p. 335, figures 8 and 9.
Geographic range : Type locality : Fern Lake, Estes Park, Colorado. Rocky Mountains and outlying ranges from Oregon and Idaho south to Wyoming. Creeks.
June-July. Common.
Alloperla (Sweltsa) occidens Frison (figure 31).
1937. Alloperla occidens Frison, Bull. Ill. Nat. Hist. Sur. 21(3) :96-97, description
of male and female; head, dorsum of abdomen, male and female genitalia,
figure 86.
86
STONEFLIES OF THE PACIFIC NORTHWEST
Geographic range : Type locality: Shucksan, Washington. British Columbia and
Montana south to Oregon. Creeks. June-July. Rare.
Discussion: Like A. revelstoki Jewett this species occurs at high elevations where it
may replace A. exquisita Frison which is similar. The two occur together at
some localities, but they can always be readily separated in the male by the
lack of a process on the 9th tergite of A. occidens.
Alloperla (Sweltsa) oregonensis Frison (figure 31).
1935. Alloperla oregonensis Frison, Trans. Amer. Ent. Soc. 61 :332, description of
male and female ; head and prothorax, pl. 11, figure 10; wings, pl. 11, figure 3;
dorsum of abdomen, pl. 12, figure 22 ; male genitalia, pl. 12, figures 18 and 22 ;
female genitalia, pl. 13, figure 32.
Geographic range : Type locality : Salmon River, Mount Hood National Forest, near
Welches, Oregon. British Columbia to Oregon. Creeks. April-June. Common.
Alloperla (Sweltsa) pacifica (Banks) (figure 31).
1895. ChloroPerla pacifica Banks, Trans. Amer. Ent. Soc. 22 :313.
1925. Alloperla pacifica, Needham and Claassen, Monog. Plecop., p. 111, description
of male and female; male and female genitalia, p. 335, figures 2 and 3.
1925. Alloperla spatulata Needham and Claassen, ibid., pp. 120-121.
1931. Alloperla spatulata, Claassen, Plecop. Nymphs, pp. 62-63, description of
nymph; nymph, pl. 17, figure 191.
1952. Alloperla (Sweltsa) pacifica, Ricker, Syst. Studies Plecop., p. 182, above
synonymy indicated.
Geographic range : Type locality: Skokomish River, Washington, British Columbia
and Montana to California. Creeks and rivers. May-July. Common.
Alloperla (Sweltsa) revelstoki Jewett (figure 31).
1955. Alloperla (Sweltsa) revelstoki Jewett, Wasmann Jour. Biol., 13(1) :152-154,
male and female.
Geographic range : Type locality : Small torrent, Mt. Revelstoke National Park,
British Columbia, elevation 6,000 feet. High elevations from British Columbia
to Mt. Hood, Oregon. Creeks. July-August. Common.
Alloperla (Triznaka) diversa Frison (figure 31).
1935. Alloperla diversa Frison, Trans. Amer. Ent. Soc. 61:333, description of male
and female ; pronotum, pl. 11, figure 5; abdomen, pl. 12, figure 20; male genitalia, pl. 12, figures 16 and 20, Pl. 13, figure 31 ; female genitalia, pl. 14, figure 40.
Geographic range: Type locality: East Fork of Hood River, Parkdale, Oregon.
Alaska to California and Utah. Creeks. May-July. Common.
Alloperla (Triznaka) pintada Ricker (figure 31).
1952. Alloperla pintada Ricker, Syst. Studies Plecop., pp. 186-187, description of
male and female; head and pronotum, male and female genitalia, p. 188, figures 147-150; placed in new subgenus Triznaka.
Geographic range : Type locality : Edloe, elevation 10,000 feet, Colorado. Washington to California ; Colorado, New Mexico, South Dakota. Creeks. May-July.
Common.
Hastaperla chilnualna Ricker (figure 32).
1952. Hastaperla chilnualna Ricker, Syst. Studies Plecop., p. 190, description of
male; male genitalia, p. 188, figure 151.
Geographic range: Type locality : Chilnualna River Camp, elevation 4,000 feet, Yo-
semite National Park, California. Washington to California. Creeks. JuneAugust. Rare.
Discussion: This coastal representative of the genus is distinguished from H. brevis
(Banks), the more widespread species, by the hooked supra-anal process which
in dorsal view is more slender than that of H. brevis.
STONEFLIES OF THE PACIFIC NORTHWEST
87
Family PERLIDAE
Subfamily ACRONEURINAE
These large stoneflies are frequently collected as both adults and nymphs
since they are common in most streams. Mystery surrounds the species Acroneuria depressa Needham and Claassen because it has not appeared in recent
collections of stoneflies from the region. The types supposedly came from the
Yakima River, Washington. California records in the Needham and Claassen
monograph (1925, p. 191) apparently refer to Acroneuria theodora Needham
and Claassen since specimens of theodora in the collection of the California
Academy of Sciences labeled by Claassen "depressa" are actually theodora.
Key to the Subgenera and Species of Pacific Northwest Acroneuria
Males
(Figure 33)
Grooves of the mesosternum widely divergent ; anal gills absent
(Subgenera Acroneuria and Calineuria)
2
Grooves of the mesosternum short and nearly parallel ; anal gills present
(Subgenus Hesperoperla)
pacifica
(okanagan)
2 (1). Head and thorax wholly blackish ; genital hooks short, cylindrical; hammer large, longitudinally rectangular, surface ridged; no spines on 9th and
theodora
10th tergites
Head and thorax pale or obscure, never wholly blackish ; genitalia not as
above ; with or without short spines on 9th and 10th tergites
3
3 ( 2 ). Vein Sc weak and indefinite at its tip ; genital hooks flat, triangular ; hammer large, transversely oval ; 9th and 10th tergites with short spines depressa
Vein Sc strong and definite at its tip ; genital hooks cylindrical ; hammer
longitudinally rectangular ; 9th or 10th tergites without spines
californica
1.
Key to the Subgenera and Species of Pacific Northwest Acroneuria
Females
(Figure 33)
Grooves of the mesosternum widely divergent ; anal gills absent
(Subgenera Aroneuria and Calineuria)
2
Grooves of the mesosternum short and nearly parallel ; anal gills present
pacifica
(Subgenus Hesperoperla)
(okanagan)
2 (1). Head and thorax wholly blackish ; subgenital plate not produced, hind
margin entire
theodora
Head and thorax pale or obscure, never wholly blackish ; subgenital plates
1.
varied
3
3
( 2 ). Vein Sc weak and indefinite at its tip ; subgenital plate cut straight across
apex
depressa
Vein Sc strong and definite at its tip ; subgenital plate not produced but
somewhat emarginate in middle
californica
STONEFLIES OF THE PACIFIC NORTHWEST
88
Key to the Subgenera and Species of Pacific Northwest Acroneuria
Nymphs
(Figure 33)
(depressa and okanagan undescribed)
Grooves of the mesosternum widely divergent; anal gills absent
(Subgenera Acroneuria and Calineuria*)
2
Grooves of the mesosternum short and nearly parallel; anal gills present
(Subgenus Hesperoperla)
pacifica
2 (1). Ocellar triangle dark ; head and thorax not strikingly patterned
theodora
Ocellar triangle yellow ; head and thorax strikingly patterned
californica
1.
Acroneuria (Acroneuria) depressa Needham and Claassen (figure 33).
1922. Acroneuria depressa Needham and Claassen, Can. Ent. 54 :253-254, description
of male and female.
b
d
e
h
Figure 33. Terminalia of Acroneuria and Claassenia. a, depressa; b, c, californica; d, e, theodora; f, g, pacifica; h, sabulosa. a, b, d, f, h, dorsal view of
male; c, e, g, ventral view of female. (a-g, Needham and Claassen, 1925; h, Ricker, 1938).
* The subgenera Acroneuria and Calineuria are distinguished on the basis of the nymphs. In
Calineuria there is an interrupted row of spinules across the occiput; this is absent in Acroneuria.
STONEFLIES OF THE PACIFIC NORTHWEST
89
1925. Acroneuria depressa Needham and Claassen, Monog. Plecop., p. 191, description of male and female ; wings, p. 323, figure 4; male and female genitalia,
p. 347, figures 15-16; egg, p. 351, figure 6.
Geographic range: Type locality : Yakima River, Lonetree, Washington. Known
only from the types collected June 30, 1882.
Acroneuria (Calineuria) californica (Banks) (figure 33).
1905. Perla californica Banks, Invert. Pac., 1:87, description of male and female.
1925. Acroneuria californica, Needham and Claassen, Monog. Plecop., pp. 192-193,
description of male and female ; male and female genitalia, p. 347, figures 1720 ; egg, p. 351, figure 1.
1931. Acroneuria californica, Claassen, Plecop. Nymphs, pp. 85-86, description of
nymph; nymph, pl. 26, figure 205.
1954. Acroneuria californica, Ricker, Proc. Ent. Soc. B. C., 51:39; placed in new
subgenus Calineuria.
Geographic range: Type locality : California. British Columbia to California. Creeks
and rivers. April-June. Abundant.
Acroneuria (Calineuria) theodora Needham and Claassen (figure 33).
1922. Acroneuria theodora Needham and Claassen, Can. Ent. 54:254, description of
male and female.
1925. Acroneuria theodora Needham and Claassen, Monog. Plecop., p. 192, description of male and female; wings, p. 323, figure 9; male and female genitalia, p.
347, figures 21-23; egg, p. 351, figure 4.
1931. Acroneuria theodora, Claassen, Plecop. Nymphs, p. 90, description of nymph;
nymph, pl. 26, figure 206.
1942. Acroncuria theodora, Frison, Bull. Ill. Nat. Hist. Sur. 22(2) :284-285, description and figures of head and prothorax, male and female genitalia, and
nymphal mouthparts.
1954. Acroneuria theodora, Ricker, Proc. Ent. Soc. B.C., 51 :39 placed in new subgenus Calineuria.
Geographic range: Type locality: Yellowstone National Park, Wyoming. Oregon
and California; Montana and Wyoming. Creeks and rivers. July-October.
Common.
Acroneuria (Hesperoperla) pacifica Banks (figure 33).
1900. Acroneuria pacifica Banks, Trans. Amer. Ent. Soc. 26:242.
1906. Acroneuria pumila Banks, Can. Ent. 38:335.
1925. Acroneuria pacifica, Needham and Claassen, Monog. Plecop., pp. 187-188;
male genitalia, p. 299, figures 11 and 12 ; wings, p. 323, figure 3; male and female genitalia, p. 347, figures 7, 9, 10; egg, p. 351, figure 3.
1925. Acroneuria Pumila, Needham and Claassen, ibid., p. 188, description and figures of male and female.
1931. Acroneuria pacifica, Claassen, Plecop. Nymphs, pp. 88-89, description of
nymph; nymphal mouthparts, pl. 5, figures 71-76; nymph, pl. 25, figure 204,
and pl. 32, figure 224.
1937. Acroneuria delta Claassen, Jour. Kans. Ent. Soc. 10:42.
1942. Acroneuria Pacifica, Frison, Pan-Pac. Ent. 18:72-73; above synonymy indicated.
Geographic range: Type locality : Washington. British Columbia to California ;
Montana to Colorado. Creeks and rivers. April-September. Abundant.
Discussion: Acroneuria okanagan Ricker (1935) from Okanagan Lake, British Columbia cannot with certainty be separated from pacifica. It may be a distinct
species in which the nymphal state is passed in lakes.
STONEFLIES OF THE PACIFIC NORTHWEST
90
Claassenia sabulosa (Banks) (figure 33).
1900. Perla sabulosa Banks, Trans. Amer. Ent. Soc. 26 :242, description of female.
1916. Adelungia arctica Klapalek, Casopis Ceske Spolei. Ent. 13 :59,78.
1925. Perla sabulosa, Needham and Claassen, Monog. Plecop., p. 101, description of
female ; wing, p. 317, figure 4.
1925. Perla languida Needham and Claassen, ibid., p. 100, description and figures of
female wing and genitalia.
1931. Acroneuria depressa (?), Claassen (not depressa Needham and Claassen 1922),
Plecop. Nymphs, p. 179, figure 207.
1938. Claassenia arctica, Ricker, Trans. Royal Can. Inst., 22:140; male and female
genitalia, p. 154, figures 16 and 17.
1942. Claassenia arctica, Frison, Bull. Ill. Nat. Hist. Sur. 22 :286 ; nymph, figures
53-54.
1952. Claassenia sabulosa, Ricker, Syst. Studies Plecop., pp. 190-191, above synonymy
indicated.
Geographic range : Type locality : Yakima, Washington. Cordilleran region from
British Columbia and southern Manitoba south through the Cascade and Rocky
Mountains to New Mexico. Creeks and rivers. July-September. Common.
Selected Bibliography
Banks, Nathan
1938. A new genus of Perlidae. Psyche 45 :136-137.
1947. Some characters in the Perlidae. Psyche 54:266 -291.
Brinck, Per.
1949. Studies on Swedish stoneflies (Plecoptera). 0 puscula Entomologica, Supplementum XI, pp. 1-250, Lund.
Castle, Gordon B.
1939. The Plecoptera of western Montana. Canadian Entomologist 71:208-211.
Claassen, P. W.
1931. Plecoptera nymphs of America (north of Mexico). Thomas Say Foundation
of the Entomological Society of America, publication 3, pp. 1-199, Charles C.
Thomas, Springfield, Illinois.
1937a. New species of stoneflies (Plecoptera). Canadian Entomologist 69:79 -82.
1937b. New species of stoneflies (Plecoptera). Journal of the Kansas Entomological
Society, 10:42-51.
1940. A catalogue of the Plecoptera of the world. Memoir 232, Cornell University
Agricultural Experiment Station, pp. 1-235, Ithaca, New York.
Dimick, R. E., and Don C. Mote
1934. A preliminary survey of the food of Oregon trout. Oregon Agricultural Experiment Station Bulletin 323, pp. 1-23, Corvallis, Oregon.
Essig, E. 0.
Plecoptera, In Insects of western North America, pp. 166-169, The Macmillan
Company, New York.
1942. Plecoptera, In College Entomology, pp. 148-158, The Macmillan Company,
New York.
1936.
Frison, T. H.
1935a. The stoneflies, or Plecoptera, of Illinois. Bulletin of the Illinois Natural History Survey, 20 :281-471.
1935b. New North America species of the genus Alloperla (Plecoptera : Chloroperlidae). Transactions of the American Entomological Society, 61 :331-344.
STONEFLIES OF THE PACIFIC NORTHWEST
91
1936. Some new species of stoneflies from Oregon (Plecoptera), Annals of the Entomological Society of America, 29:256-265.
1937. Descriptions of Plecoptera, with special reference to the Illinois species. Bulletin of the Illinois Natural History Survey, 21:78-99.
1942a. Descriptions, records, and systematic notes concerning western North American stoneflies (Plecoptera). Pan-Pacific Entomologist, 18:9 -16, 61-73.
1942b. Studies of North American Plecoptera, with special reference to the fauna of
Illinois. Bulletin of the Illinois Natural History Survey, 22(2) :235-355.
1944. Three new species of Capnia from Colorado (Plecoptera: Capniidae). Trans-
actions of the American Entomological Society, 69:151-157.
Gaufin, A. R., and C. M. Tarzwell
1952. Aquatic invertebrates as indicators of stream pollution. Public Health Reports, 67 (1) :57-64.
Hanson, John F.
1941. Studies on the Plecoptera of North America. II. Bulletin of the Brooklyn Entomological Society, 36(2) :57-66.
1942. Records and descriptions of North American Plecoptera. Part II. Notes on
North American Perlodidae. American Midland Naturalist, 28 :289-407.
1943a. Descriptions of new North American Plecoptera. II. Proceedings of the Entomological Society of Washington, 45 (4) :85-88.
1943b. Records and descriptions of North American Plecoptera. Part III. Notes on
Isogenoides. American Midland Naturalist, 29 :657-669.
1943c.
Studies on the Plecoptera of North America. IV. Further notes on the Cap-
niidae. Bulletin of the Brooklyn Entomological Society, 38(5) :155-163.
1946. Comparative morphology and taxonomy of the Capniidae (Plecoptera). American Midland Naturalist, 35:193 -249.
1949. Studies on the Plecoptera of North America. V. Notes on Isogenoides. Bulletin of the Brooklyn Entomological Society, 44(4) :109-116.
Hanson, John F., and Jacques Aubert
1952.
First supplement to the Claassen catalogue of the Plecoptera of the world,
pp. 1-23. Privately printed.
Harden, Philip H., and Clarence E. Mickel
1952. The stoneflies of Minnesota (Plecoptera). University of Minnesota Agricultural Experiment Station, Technical Bulletin 201, pp. 1-84.
Hoppe, Gertrude N.
1938. Plecoptera of Washington. University of Washington publications in biology,
4:139-174.
Hynes, H. B. N.
1941. The taxonomy and ecology of the nymphs of British Plecoptera with notes
on the adults and eggs. Transactions of the Royal Entomological Society,
London, 91(10).
Jewett, Stanley G., Jr.
1954a. New stoneflies (Plecoptera) from western North America. Journal of the
Fisheries Research Board of Canada, 11(5) :543-549.
1954b. New stoneflies (Plecoptera) from California and Oregon. Pac-Pacific Entomologist, 30(3) :167-179.
1955. Notes and descriptions concerning western North American stoneflies (Plecoptera) . Wasmann Journal of Biology, 13(1) :145-155.
Neave, Ferris
1929. Reports of the Jasper Lakes investigations. II. Plecoptera, In Contributions to
Canadian Biology and Fisheries, New Series 4:159-168.
1933. Some new stoneflies from western Canada. Canadian Entomologist, 65:235-238.
STONEFLIES OF THE PACIFIC NORTHWEST
92
1934.
Stoneflies from the Purcell Range, British Columbia. Canadian Entomologist,
66 :1-6.
Needham, J. G., and P. W. Claassen
1925. A monograph of the Plecoptera or stoneflies of America north of Mexico.
Thomas Say Foundation of the Entomological Society of America, publication
2, pp. 1-397, Lafayette, Indiana.
Newcomer, E. J.
1918. Some stoneflies injurious to vegetation. Journal of Agricultural Research,
13 :37-41.
Ricker, Wm. E.
1935. New Canadian perlids (Part II). Canadian Entomologist, 67:256-264.
1938. Notes on specimens of American Plecoptera in European collections. Transactions of the Royal Canadian Institute, 22 :129-156.
1943. Stoneflies of southwestern British Columbia. Indiana University publications,
Science Series Number 12, pp. 1-145, Bloomington, Indiana.
1950. Some evolutionary trends in Plecoptera. Proceedings of the Indiana Academy
of Sciences, 59:197-209.
1952.
Systematic studies in Plecoptera. Indiana University publications, Science
Series Number 18, pp. 1-200, Bloomington, Indiana.
Index to the Genera and Species of Stoneflies of the
Pacific Northwest
Synonyms are in parentheses. Principal page references are in boldface type.
abbreviata Frsn
A croneuria Pict
aestivalis Ndm. & Clsn
agassizi Rick
albertensis Ndm. & Clsn
Alloperla Bks
(americana Klp.)
Page
Page
13, 51
16, 21, 22, 87, 88
14, 65, 66, 67
13, 51, 52
16, 81, 83, 84
15, 21, 22, 78
11, 26, 28, 30, 32
cornuta Clsn
14, 65
Cu/tus Rick
9, 14, 60, 61, 62, 63
curvata Hanson
12, 42, 44
cygna Jewett
11, 26, 29, 30, 31, 33
decepta Frsn
16, 78, 79, 81 83
delicata Frsn
12, 27, 29, 31, 33
delicatula Clsn
16, 89
(delta Clsn.)
11, 26, 28, 30, 31, 32
depressa Bks
16, 87, 88
depressa Ndm. & Clsn
12, 36, 37, 38
Despaxia Rick
11, 25, 26, 30, 31, 33
dimicki Frsn
43
distincta Frsn
15, 20, 22
Diura Billberg
16, 80, 81, 83, 86
diversa Frsn
13
Doddsia Ndm. & Clsn
64
16, 90
(arctica Klp.)
14, 20, 22, 58, 60, 62
Arcynopteryx Klp
12, 36, 37 38
augusta Bks
14, 19, 58, 60, 61, 64
aurea Smith
16, 78, 83, 84
autumna Hoppe
55, 56, 57
badia Hag
13, 54
(banksii Ndm. & Clsn.)
besametsa Rick......... 12, 18, 28, 29, 30, 31, 34
11, 26, 28, 31
bifurcata Clsn
12, 39
(bilobata Clsn.)
16, 19, 79, 81, 82, 83, 85
borealis Bks
1, 13, 20, 21, 53
Brachyptera Nwpt
12, 39
(bradleyi Clsn.)
14, 58, 60, 61, 63
bradleyi Smith
13, 18, 49, 50
brevicauda Clsn
11, 23, 24, 25
brevis Bks
16, 87, 89
californica Bks
11, 26, 28, 30, 31 32
californica Clsn
1, 9, 14, 55, 56, 57
californica Nwpt
16, 87, 88
Callineuria Rick
15, 20, 58, 68
Calliper la Bks
11, 23, 24
campanula Jewett
2, 6, 12, 19, 21, 41, 42
Capnia Pict
15, 72
(cascadensis Hoppe)
cataractae Neave....12, 25, 28, 29, 30, 34, 35
14, 58, 64, 65
Chernokrilus Rick
16, 82, 86
chilnualna Rick
15, 72
(chrysannula Hoppe)
cinctipes Bks
claasseni Frison
Claassenia Wu
collaris Bks
coloradensis Bks
coloradensis Clsn
colubrinus Hag
Dolkrila Frsn
(dolobrata Smith)
63
6, 55, 56 57
dorsata Say
16, 84
(dubia Frsn.)
ebria Hag
15, 69, 70, 71, 72
13, 42, 44, 45
elevata Frsn. (Capnia)
16, 83
(elevata Frsn.) (alloperla)
13, 42, 44, 45
elongata Clsn
14, 65, 66, 67
elongatus Hag
13, 42, 44, 45
erecta Jewett
13, 20, 21, 49, 50
Eucapnopsis Okm
13, 42, 44, 45
excavata Clsn
68
expansa Clsn
16, 79, 81, 82, 83, 85
exquisita Frsn
11, 23, 24
fenderi Jewett
fibula
2
Clsn
fidelis Bks
flexura Clsn
16, 79, 81, 83, 85
11, 29, 31, 32
11, 25, 26, 30, 31, 33
foersteri Rick
15,
(frontium Neave.)
12, 36, 37, 38,
forcipata Frsn
16, 78, 79, 82, 83,
forcipata Neave
(fraseri Rick.)
16, 80, 81, 82,
fraterna Frsn
12, 27, 29,
frigida Clsn
14, 58, 60,
Frisonia Rick
15, 76,
frontalis Bks
15, 69, 70, 71,
fulva Clsn
13,
(fumigata Clsn.)
13,
(fumosa Bks.)
15, 69, 70, 71,
fusca Ndm. & Clsn
13, 43, 44,
glabra Clsn. (Capnia)
12,
(glabra Clsn.) (Leuctra)
12, 26, 27, 29, 35
17
16, 21, 22, 90
12, 40, 41
16, 79, 81, 82, 83, 85
43
6, 14, 19, 53, 65, 66, 67
columbiana Clsn. (Capnia)_.12, 42, 43, 44
12, 27,
columbiana Clsn. (Nemoura)
29, 35
9, 59, 60, 62, 64
compacta McL
34
comp/eta Wlk
complicata Clsn
confusa Clsn
15, 58
12, 39, 40
12, 43
93
74
39
84
67
85
35
62
77
72
52
52
72
45
38
e
glabra Clsn. (Nemoura)
34
gracilaria Clsn
13, 42, 44, 45
grandis Bks
13, 51, 52
gravitans Ndm. & Clsn 15, 69 70, 71, 72
Hastaperla Rick
16, 21, 22, 78
12, 27, 28, 29, 35
haysi Rick
Hesperoperla Bks
16, 87, 88
infuscata Clsn
12, 36, 37, 38
(incesta Bks.)
14, 67
(insipida Hoppe)
15, 74
interrupta Clsn
12, 26, 27, 31, 34
irregularis Bks
14, 59, 60, 61, 62
13, 18, 20, 21, 50
Isocapnia Bks
14, 22, 58, 65
Isogenoides Klp
14, 20, 22, 58, 64
Isogenus Nwm
3, 15, 20, 22, 58, 68
Isoperla Bks
jewetti Frsn
13, 42, 44, 46
15, 20, 22
Kathroperla Bks
kincaidi Frsn
12, 39, 40
(kincaidi Hoppe)
13, 54
15, 76
knowltoni Frsn
15, 65
Kogotus Rick
occidentalis Bks. (Leuctra)
37, 38, 39
occidens Frsn
16, 80, 81, 83, 85
oenone Neave
13, 43, 47
(okanagan Rick.)
16, 87, 88, 89
oregona Frsn
13, 43, 46, 47
oregonensis Clsn
12, 27, 29, 35, 36
oregonensis Ndm. & Clsn
13, 52, 53, 54
oregonensis Frsn
16, 80, 81, 83, 86
Osobenus Rick
15, 58, 64
Ostrocerca Rick
11, 25, 31
pacifica Bks. (Acroneuria)
1, 16, 19,
87, 88, 89
pacifica Bks. (Alloperla)..16, 80, 81, 83, 86
pacifica Bks. (Brachyptera)....3, 13, 52, 53,
pallida Bks
pallidula Bks
54, 55
13, 52, 53, 54, 55
16, 78, 79, 82, 83 84
(pallidura Clsn.)
13, 54
Paraleuctra Hanson
12, 36, 37 38
parallela Frsn
9, 14, 53, 59, 60, 62, 64
Paraperla Bks
15, 20, 22
patricia Frsn
15, 17, 70, 71, 73, 74
Peltoperla Ndm
11, 17, 21, 23
perdita Bks
15, 19, 76 77
Perlinodes Ndm. & Clsn
14, 58, 60
Perlomyia Bks
12, 18, 21, 36, 41
perplexa Frsn
11, 26, 29, 31, 32
petersoni Ndm. & Christenson....15, 70, 71,
lamba Ndm. & Clsn
16, 80, 81, 83, 85
16, 90
(languida Ndm. & Clsn.)
12, 18, 21, 36
Leuctra Steph
13, 42, 44, 46
licina Jewett
13, 43, 44 47
lineata Hanson
lineosa Bks
16, 78, 83, 84
(lobata Frsn.)
Page
12, 18, 36,
11, 32
longiseta Bks
15, 70, 71, 72, 73
15, 69, 71
luctuosa Bks
Malenka Rick
11, 25, 26, 29
mariana Rick
11, 23, 24, 25
marmorata Ndm.&Clsn...15, 69, 70, 71, 72, 74
9, 14, 17, 52, 53, 55
maura Pict
medveda Rick
16, 78, 79, 81, 83
Megaleuctra Neave
12, 18, 21, 36, 39
Megarcys Klp
14, 58, 59, 60
melia Frsn
13, 43, 46, 47
misnomus Clsn
14, 64 65, 66
modestus Bks
15, 65, 68
mormona Bks
15, 70, 71, 73, 74
Mose lia Rick
12, 36, 38
13, 42, 46, 47
nana Clsn
Neaviperla Rick
16, 78
2, 11, 17, 21, 25, 53
Nemoura Pict
nigripennis Bks
13, 52, 53 54
(nivalis Fitch)
14, 55
(nivalis Neave)
12, 43
nonus Ndm. & Clsn
15, 65, 66, 68
(obscura Bks.)
16
12, 27, 29, 30, 31, 33, 34
obscura Frsn
obscura Ndm. & Clsn
14, 65
occidentalis Bks. (Brachyptera)
13, 52,
53, 54
74, 75
petila Jewett
13, 42, 46, 47
phalerata Smith
15, 68, 71 73, 74
picticeps Hanson
14, 59, 60, 62
pilatus Frsn
14, 65, 66, 67
pinta Frsn
15, 70, 71, 73, 74
pintada Rick
16, 80, 81, 82, 83, 86
Podmosta Rick
11, 29, 31
porrecta Jewett
13, 43 46, 47
princeps Bks
9, 14, 55, 56, 57
producta Clsn
12, 26, 28, 31, 34
projecta Frsn. (Capnia)._..13, 18, 43, 46, 48
(projecta Frsn.) (Leuctra)
12
promota Frsn
13, 42, 46, 48
Prostoia Rick
12, 29, 31
(pseudoproducta Frsn.)
34
Pteronarcella Bks
14, 20, 21, 55, 56, 57
Pteronarcys Nwm 2, 14, 20, 21, 55, 56, 57
(pumila Bks.)
16, 89
purcellana Neave
quadrispinula Jewett
rainiera Jewett
regularis Hag
revelstocki Jewett
Rickera Jewett
(rossi Rick.)
94
12, 36, 38, 39
11, 23, 24
15, 70, 71, 73, 74
14, 55, 56, 57
16 80, 81, 83, 86
15, 20, 22, 68, 75
11, 33
Page
Page
sabulosa Bks
sara Clsn
serrata Ndm. & Clsn
Setvena Rick
severa Hag
sextuberculata Jewett
16,
88, 90
thujae Rick
9, 12, 36, 37,
16, 78, 79,
14,
16, 78, 79 81,
13, 42,
38, 39
81, 83
58, 60
82, 83
46, 48
tibialis Bks
tina Rick
signata Bks
signata Hag
Skwala Rick
(sobria Frsn.)
Soliperla Rick
(solitaria Frsn.)
sopladora Rick
sordida Bks
sorptus Ndm. & Clsn
Soyedina Rick
(spatulata Ndm. & Clsn.)
spectabilis Neave
spenceri Rick
subtruncata Hanson
Suwallia Rick
Sweltsa Rick
Taenionema Bks
Taeniopteryx Pict
(thalia Rick.)
theodora Ndm. & Clsn
(titusi Bks.)
62
tostonus Rick
trictura Hoppe
Triznaka Rick
(tuberculate Frsn.)
62
tun:1,d¢ Clsn
81
14, 59, 60, 61,
14, 58, 60,
12,
11,
12,
15,
15, 70, 71, 73,
14, 65,
12, 25,
51, 53
58, 60, 61, 63
26, 28, 31, 33
14, 67
13, 50,
14,
11,
14, 65, 66, 67
15, 70, 71, 75
16, 78
12, 34
13 42, 48, 49
13, 42, 48, 49
umpqua Frsn
12, 18, 40, 41
utahensis Ndm. & Clsn
15, 20, 22
Utaperla Rick
14, 64
(vagans Smith)
13, 49, 50
vedderensis Rick
13, 42, 48, 49
venosa Bks
15, 22, 75
venusta Jewett
12, 25, 29
Visoka Rick
12, 26, 27, 29, 30, 36
wahkeena Jewett
14, 62
(walkeri Rick.)
14, 59, 60, 61, 62
watertoni Rick
13, 43, 49
willametta Jewett
15, 22, 64, 66, 68
yakimae Hoppe
11, 23
Y oraperla Rick
yosemite Ndm. & Clsn 14, 59, 60, 61, 63
12, 26, 29
Zapada Rick
13, 43, 49
zukeli Hanson
41
23
41
77
75
66
31
86
12, 18, 36, 39
13, 50, 51, 52
14, 59, 60, 61, '62
16, 78
16, 78
13
14, 20, 21
16, 83
16, 87, 88, 89
95
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