SPECIES FACT SHEET
Common Name: Marsh damsel bug
Scientific Name: Nabis propinquus = Nabicula propinq ua (Reuter, 1872)
Phylum: Mandibulata
Class: Insecta
Order: Hemiptera
Family: Nabidae
Subfamily: Nabinae
Genus: Nabis
Subgenus: Nabicula
Taxonomic Note:
The Nabicula “group” has been treated both as its own genus and as a
subgenus of Nabis by various authors. Since the most recent treatments
(Kerzhner 1996, Kerzhner & Henry 2008) present this group as a subgenus of
Nabis, the current name for the marsh damsel bug is Nabis propinquus.
Conservation Status:
Global Status (2001): G5 - Secure
National Status (United States): NNR
State/Province Statuses: Oregon (S2), British Columbia (S1)
(NatureServe 2012).
Technical Description:
Nabis propinquus is a slender brown terrestrial hemipteran in the Nabidae
(damsel bug) family (Applegarth 1995). This family is comprised of a small
group of important generalist predators best known for their frequent use in
biological control programs to manage insect pests on agricultural crops
(Kerzhner & Henry 2008). Like other heteropterans, the mouthparts are of a
unique piercing-sucking type, and the basal portion of the front wing is
thickened and leathery, while the apical portion is membranous. Members of
this family are mostly dull-brownish, occurring in both short-winged
(brachypterous) and long-winged (macropterous) forms (Maw et al. 2000). In
North America, this family is distinct from other true bugs by the front femora
being slightly enlarged (swollen), and the membrane of the hemelytra (when
developed) having a number of small cells around the margin (Triplehorn &
Johnson 2005, Arnett 2000). This family is further described as follows (Maw et
al. 2000): Ocelli are present; the labium is four-segmented. The fore legs have a
dense pad of hairs (fossula spongiosa) at the distal end of the tibia. The costal
fracture of the hemelytra may be present or absent. The membrane of the
hemelytra has two or three elongate cells, and usually has emanating veins
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and a stub. The abdomen has three dorsal scent gland openings between terga
4/5, 5/6, and 6/7. The male genitalia are usually symmetrical (Maw et al.
2000).
The Nabidae family contains two subfamilies, 11 genera, and 39 species in
North American (Kerzhner & Henry 2008, Henry 2009). The marsh damsel bug
belongs to the Nabinae subfamily, Nabis genus. Members of this genus are 6 to
9 mm in length, slender, light to dark brown, and have the front femora slightly
enlarged (BugGuide 2013). The Nabis genus is further divided into subgenera,
including the subgenus Nabicula, to which this species belongs. There are a
total of six species in the Nabicula subgenus in North America (Henry & Latttin
1988). Among these, Nabis propinquus is highly divergent morphologically, to
the extent that it has been separated from the other five species into its own
subgroup, the former subgenus Limnonabis. (This subgenus became obsolete
when all of the species in the former Nabicula genus were shifted to Nabis, and
Nabicula was reduced to subgenus status (Kerzhner 1996)). Nomenclature
aside, N. propinquus is distinguished from other North American members of
the Nabicula subgenus by the following characters: diverging posterior lobe of
the head; recurved connexivum of the male; and the presence of three or four
sclerites in the aedeagus (Asquith & Lattin 1990). In addition, the yellowish,
elongate, parallel-sided abdomen help identify this species among its close
relatives (BugGuide 2013). According to Harris (1928), this species is the
longest of the American Nabids, and is easily recognized by its form.
A full description of this species is as follows (Harris 1928):
Slender, greatly elongate, pubescent; testaceous, an interrupted median
line extending from base of tylus to tip of abdomen and a broad stripe on
either side of body for its full length fuscous. Femora fusco-maculate.
Head long, more than a third longer than broad, faintly widened behind
the eyes. Eyes only moderately large, the length of one equal to the width
of vertex. Ocelli prominent. Antennae long, darkened distally, segment I
much longer than the width of head through eyes. Rostrum with
segments II and III subequal, each much shorter than antennal segment
I. Pronotum with long collar, the anterior lobe with the cicatrices
darkened; the posterior lobe finely punctulate. Scutellum with a
prominent, semicircular, shiny spot on either side basally. Abdomen
above with an interuppeted fuscous stripe to either side of the median
dark line; the connexivum horizontal. Legs long, the front and mid
femora thickly clothed beneath with short hooked hairs and more thinly
so with shorter piceous spinules; front femora about six times as long as
thick; posterior tibiae clothed with short hairs. Male narrower than
female, the genital segments long, prominent, the clasper distinctive.
Female with abdomen rather sharply angular at apex, the apical margin
of last abdominal segment emarginated. Brachypterous form: pronotum
longer than broad, the lobes indistinctly marked off, the basal margin
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roundly emarginated (more strongly so in male). Hemelytra extending
almost to apex of second abdominal segment, obtusely rounded behind,
without membrane. Length 9-12 mm; width 1.32-1.68 mm (at abdomen,
1.32-2.82 mm). Macropterous form: pronotum broader than long, the
posterior lobe arched. Hemelytra somewhat translucent, finely
punctulate; membrane extending onto base of last abdominal segment.
Length 12 mm; width 2.1 mm (Harris 1928).
Although N. propinquus exhibits both macropterous (fully-winged) and
brachypterous (short-winged) morphs, the macropterous condition is very rare
relative to the brachypterous morph. For example, only 2 of the 45 females and
1 of the 29 males examined by Asquith & Lattin (1990) were macropterous. In
addition to wing polymorphism, this species also exhibits sexual dimorphism in
which the females are larger than males and differ in various body proportions
(see Asquith & Lattin 1990 for details).
See Attachment 4 in the Appendix for a photograph and illustrations of the
male and female macropterous and brachypterous morphs of this species. The
genitalia of this species are illustrated in Asquith & Lattin (1990).
Immature: Immature nabids have a long, slender, 4 segmented labium arising
from the anterior part of the head (Elvin & Sloderback 1984). They also have
long, slender antennae, apical tarsal claws, and usually 3-4 pairs of scent
glands present on the abdomen. The labium is not located in a rostral groove in
the gular region (Elvin & Sloderback 1984). The nymphal instar of a particular
immature nabid can be determined by assessing the amount of wing pad
development (see Elvin & Sloderback 1984 for details). Within the family, there
is only limited information on identifying nymphal stages to genus or species.
Nymphs of the genus Nabis are distinguished from the related genus
Hoplistoscelis largely by body shape (Nabis is generally narrower than
Hoplistoscelis) (Elvin & Sloderback 1984). A description of the nymph of N.
propinquus is not known.
Life History:
Nabid bugs are aggressive generalist predators, feeding on a wide variety of
small arthropods including caterpillars, aphids, and plant bugs (Marshall
2006, Triplehorn & Johnson 2005). Nabid nymphs are active shortly after
hatching and begin feeding immediately, often on prey considerably larger than
themselves (Lattin 1989).
The phenology of this species is poorly known. Known records in Oregon are
from July and September (OSAC 2013, Asquith & Lattin 1990). Rangewide, this
species has been collected from June to September, with the majority of
records in July and August (Asquith & Lattin 1990). Nabids tend to overwinter
as adults (Applegarth 1995, Lattin 1989). Members of this genus can be
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univoltine or multivoltine, producing one to five generations per year,
depending on location (BugGuide 2013).
Dispersal behavior in N. propinquus has not been examined. The macropterous
(fully-winged, flight capable) form of some adult nabids are known to move
considerable distances (Lattin 1989), probably in response to instable habitats
or food sources. Since this species is known primarily in the brachypterous
(reduced wing) form (Asquith & Lattin 1990), its dispersal potential is probably
limited by the reduced flight ability of this wing morph.
Overall, many aspects of this species biology are in need of study, including
dietary preferences, mating behavior, oviposition site selection, number of eggs
laid, development time, life span, number of generations per year, dispersal
behavior, and overwintering behavior and habitat.
Range, Distribution, and Abundance:
This species is widely distributed across North America. In Canada it is known
from Alberta, British Columbia, Northwest Territories, Ontario, Quebec,
Saskatchewan. Manitoba, New Brunswick, Prince Edward Island and Nova
Scotia (Henry & Lattin 1988, Scudder 1994, Maw et al. 2000, Asquith & Lattin
1990). In the United States, it is reported from Illinois, Iowa, Maine, Maryland,
Massachusetts, Michigan, North Dakota, Nebraska, Kansas, Oklahoma, New
Jersey, New York, Ohio, Oregon, South Dakota, and Wisconsin (Henry & Lattin
1988, reviewed in Kerzhner & Henry 2008, Applegarth 1995, Asquith & Lattin
1990, GBIF 2013). Since this species has not yet been found in the arid Intermountain west region, the Oregon populations are considered disjunct from the
main distribution (Asquith & Lattin 1990). See the Conservation
Considerations section, below, for further discussion of the biogeography of
this species.
In Oregon, this species appears to be restricted to the Pacific Coast (Asquith &
Lattin 1990). Known records in Oregon are from two separate areas along the
coast, in Tillamook and Coos Counties (Applegarth 1995, OSAC 2013). This
species has not been found in the Willamette Valley or Puget Trough areas of
Oregon and Washington (Asquith & Lattin 1990). Asquith & Lattin (1990) note
the possibility that this species may occur in coastal marshes of Washington.
BLM/Forest Service lands: This species is Suspected on Siuslaw National
Forest based on the presence of large coastal stretches of Siuslaw NF land
between and in the vicinity of the known Oregon sites. It is also Suspected by
Salem and Eugene BLM Districts, based on their coastal lands near the known
sites.
Abundance: Abundance estimates for this species have not been conducted.
Most collections have been of one to two individuals, although one Oregon
collection was of 16 individuals (12 male, 4 female) (Asquith & Lattin 1990).
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Habitat Associations:
This species lives in wet environments where it is found on the ground or in
low vegetation (Asquith & Lattin 1990). Rangewide, it occurs in moist, riparian
or marshy habitats (Asquith & Lattin 1990). According to Harris (1928), this
species frequents the edges of marshes and ponds where reeds and sedges
flourish. In Oregon, coastal salt marshes are the only known habitat for this
species (Applegarth 1995). In British Columbia this species is also known from
beach habitat (Scudder 1994).
Threats:
Threats to this species include conversion and fragmentation of coastal
marshes and wetlands, loss and degradation of sand dune systems and
riparian areas, and encroachment of exotic vegetation.
Conservation Considerations:
According to Asquith & Lattin (1990), the origin of the highly disjunct Oregon
coast population is perplexing. Lattin (1966) suggested that this population
might be an introduction from the eastern United States, but Asquith & Lattin
(1990) believed this to be unlikely, considering the restricted habitat of this
species and the fact that the Oregon population displays a slightly different
genitalic structure than the eastern populations (see Asquith & Lattin 1990 for
further details). In their thorough examination of the biogeography of this
species, Asquith & Lattin (1990) present the following conclusions (slightly
paraphrased):
We hypothesize that this species (or its direct ancestor) was present in
North America during the Eocene period, at which time there were few
barriers to impede East-West movement and a contiguous distribution
across the northern latitudes would have been possible. Beginning in the
Miocene, orogenic activity in western North America resulted in
topographical geographic barriers and, perhaps more importantly,
increased aridity in the Intermountain region. Because N. propinquus
lives in moist, riparian habitats, this dramatic change in climate and
terrain would have restricted mobility and could have led to the
extinction of many, or all of the intervening populations. This is merely a
hypothesis of course, and we cannot actually date the separation of the
west coast population and it is possible that it is a much more recent
event. The climate of the northern United States during the Pleistocene
periods was much more mesic than the present, with abundant, large
shallow lakes and marshes throughout the Great Basin province. This
would have provided abundant habitats for N. propinquus from the Rocky
Mountains west [to the Pacific Coast]. With the advent of the
Hypsithermal and higher temperatures, these habitats in this area
largely disappeared, which could have left the coastal population isolated
from those north and east of the Rockies. This hypothesis would be
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corroborated if relictual populations of N. propinquus were found in
isolated marshes in the northern Great Basin (Asquith & Lattin 1990).
Inventory: Unlike some of the commonly encountered species of Nabis species
that occur on vegetation in a variety of habitats, Nabis propinquus is rare in
museum collections (Asquith & Lattin 1990), probably due to a combination of
rarity, restricted habitat, and limited sampling effort. Further surveys are
needed for this species in Oregon, and will be critical in evaluating its current
status and habitat use in the region. Initial surveys are recommended in
coastal salt marshes on Siuslaw National Forest in the area between and in the
vicinity of known sites. This species was last documented at both the Tillamook
and Coos County coastal sites in 1988 (OSAC 2013, Asquith & Lattin 1990).
In British Columbia, this species is also considered a priority for inventory and
descriptive research, due to being very rare or endangered at both the
provincial and national levels (Scudder 1996).
Management: Protect all known and potential sites from practices that would
adversely affect this species or its habitat. Management designed to limit the
encroachment of exotic vegetation may be important at some sites.
Research: Many aspects of this species’ biology are in need of study including
food preferences, mating behavior, oviposition site selection, number of eggs
laid, development time, life span, number of generations per year, and
overwintering behavior.
Prepared by: Sarah Foltz Jordan, Xerces Society for Invertebrate Conservation
Date: 9 April 2013
Edited by: Sarina Jepsen, Xerces Society for Invertebrate Conservation
Date: 10 April 2013
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ATTACHMENTS:
(1)
References
(2)
List of pertinent or knowledgeable contacts
(3)
Map of known records in Oregon
(4)
Photograph and illustrations of this species
(5)
Survey protocol for this species
ATTACHMENT 1:
References.
Applegarth, J.S. 1995. Invertebrates of special status or special concern in the
Eugene district. U.S. Department of the Interior, Bureau of Land Management.
126 pp.
Arnett, R.H., Jr. 2000. American Insects, A Handbook of the Insects of America
North of Mexico, 2nd edition, CRC Press, Boca Raton, FL. 1003 pp.
Asquith. A. & J.D. Lattin. 1990. Nabicula (Limnonabis) propinquus (Reuter)
(Heteroptera: Nabidae): dimorphism, phylogenetic relationships and
biogeography. Tijdschrift voor Entomologie 133: 3-16.
Blinn, R.L. 1995. Phorticus collaris Stål: A nabid new to Eastern North America
(Heteroptera: Nabidae). Journal of the New York Entomological Society 103:
216-218.
BugGuide 2013. Nabis. Available at: http://bugguide.net/node/view/12327
(Accessed 4 April 2013).
Elvin, M.K. and P.E. Sloderbeck 1984. A key to the nymphs of selected species
of Nabidae (Hemiptera) in the southeastern USA. Fla. Entomol. 67: 269-273.
Global Biodiversity Information Facility (GBIF). Nabicula propinquus. Available
at: http://data.gbif.org/occurrences/350330209 and:
http://data.gbif.org/occurrences/350330207 (Accessed 4 April 2013).
Harris, H.M. 1928. A monographic study of the Hemipterous family Nabidae as
it occurs in North America. Entomologica Americana 9: 1-97.
Henry, T.J. 2009. Biodiversity of Heteroptera. Chapter 10. Pp. 223–263 In:
Foottit, R.G.; Adler, P.H. (eds) 2009: Insect Biodiversity: Science and Society.
Wiley-Backwell, Oxford, U.K. 656 pp.
Henry, T.J. and J. Brambila. 2003. First report of the neotropical damsel bug
Alloeorhynchus trimacula (Stein) in the United States, with new records for two
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other nabid species in Florida (Heteroptera: Nabidae: Prostemmatinae).
Proceedings of the Entomological Society of Washington 105: 801-808.
Henry, T.J. and J.D. Lattin. 1988. Family Nabidae Costa. 1853. The damsel
bugs, pp. 508-520. In Henry. T. J. and R. C. Froeschner. eds. Catalog of the
Heteroptera, or true bugs, of Canada and the continental United States. E.J.
Brill, Leiden and New York. 958 pp.
Kerzhner I.M. and T.J. Henry. 2008. Three new species, notes and new records
of poorly known species, and an updated checklist for the North American
Nabidae. Proceedings of the Entomological Society of Washington 110(4): 988–
1011.
Kerzhner I.M. 1996. Family Nabidae. Catalogue of the Heteroptera of the
Palaearctic Region 2: 84-107.
Lattin, J.D. 1989. Bionomics of Nabidae. Annual Review of Entomology 34:
383–400.
Marshall, S. 2006. Insects: their natural history and diversity: with a
photographic guide to insects of eastern North America. Firefly Books, Buffalo,
New York. 718 pp.
Maw, H.E.L., Foottit, R.G., Hamilton, K.G.A. and G.G.F. Scudder. 2000.
Checklist of the Hemiptera of Canada and Alaska. NRC Research Press.
Ottawa, Ontario. 220 pp.
NatureServe. 2013. “Nabicula propinquus.” NatureServe Explorer: An online
encyclopedia of life [web application]. Feb. 2009. Version 7.1. NatureServe,
Arlington, Virginia. Data last updated: October 2012. Available at:
www.natureserve.org/explorer (Accessed 11 March 2013).
Oregon State University Arthropod Collection (OSAC). 2013. Specimen data
gathered by Ashley Clayton, contractor for the Xerces Society.
Reuter, 0.M., 1872. Nabidae novae et minus cognitae. Bidrag till Nabidernas
kannedom. Ofversigt af Kongliga Vetenskaps -Akademiens Forhandlingar 29(6):
79-96.
Scudder, G.G.E. 1994. An annotated systematic list of the potentially rare and
endangered freshwater and terrestrial invertebrates in British Columbia.
Entomological Society of British Columbia, Occasional Paper 2: 1-92.
Scudder, G.G.E. 1996. Terrestrial and freshwater invertebrates of British
Columbia: priorities for inventory and descriptive research. Res. Br., B.C. Min.
8
For., and Wildl. Br., B.C. Min. Environ., Lands and Parks. Victoria, B.C. Work.
Pap. 09/1996.
Triplehorn, C. and N. Johnson. 2005. Introduction to the Study of Insects.
Thomson Brooks/Cole, Belmont, CA. 864 pp.
ATTACHMENT 2: List of pertinent or knowledgeable contacts
Michael Schwartz, Research Affiliate, Insect Biosystematics, Canadian National
Collection of Insects.
Thomas Henry, Smithsonian National Museum of Natural History, Washington
DC.
John D. Lattin, Oregon State University, Corvallis, Oregon.
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ATTACHMENT 3:
Map of known records in Oregon and Washington
Known records of Nabis propinquus in Oregon, relative to BLM and Forest
Service lands.
10
Known records of Nabis propinquus in Tillamook County, Oregon, showing
proximity to Suislaw National Forest.
11
ATTACHMENT 4:
Photograph of this species
Nabis propinquus brachypterous adult female, dorsal view. Photograph by
Ashley Clayton for The Xerces Society, used with permission.
12
Nabis propinquus brachypterous male adult, dorsal view. Illustration from
Asquith & Lattin (1990).
13
Nabis propinquus adults, dorsal view. Macropterous female (A), macropterous
male (B). Illustration from Asquith & Lattin (1990).
ATTACHMENT 5:
Survey Protocol for this species
Survey Protocol:
Nabis propinquus
Where:
This species is known from very few collections in Oregon, probably due (at
least in part) to limited sampling effort. Further surveys are needed for this
species in Oregon, and will be critical in evaluating its current status and
habitat use in the region. Initial surveys are recommended on Siuslaw National
14
Forest in the area between and in the vicinity of known sites. This species was
last documented at both the Tillamook and Coos County coastal sites in 1988
(OSAC 2013, Asquith & Lattin 1990).
Surveys in Oregon should target coastal salt marshes, the only known habitat
in the state. Rangewide, this species inhabits moist, riparian areas.
When:
Surveys for this species are recommended in summer. Known records in
Oregon are from July and September (OSAC 2013, Asquith & Lattin 1990).
Rangewide, this species has been collected from June to September, with the
majority of records in July and August (Asquith & Lattin 1990). Nabids tend to
overwinter as adults (Applegarth 1995, Lattin 1989). Members of this genus
can be univoltine or multivoltine, producing one to five generations per year,
depending on location (BugGuide 2013).
How:
Visual searches and sweep-netting in known habitat (coastal marshes) are
probably the most appropriate survey method at this time. Window traps (e.g.,
plexiglass panels in tubs of soapy water) may also be useful, as these traps
(placed 1 to 7 m off the ground) have been successful at collecting other
members of this family (Lattin 1989). Ultraviolet light traps have also been
used to collect nabids (Blinn 1995), and many nabid species are known to be
attracted to visible light (BugGuide 2013).
After capture, voucher specimens should be placed immediately into a kill jar
until they can be pinned. A field catch can also be temporarily or permanently
stored in 75% ethyl alcohol but the alcohol will cause some colors to fade
(Triplehorn & Johnson 2005). Adult specimens should be pinned through the
scutellum (Triplehorn & Johnson 2005). Juveniles are best preserved in vials
containing 75% ethyl alcohol. Collection labels should include the following
information: date, collector, detailed locality (including geographical
coordinates, mileage from named location, elevation, etc.), and detailed
habitat/host plant. Complete determination labels include the species name,
sex (if known), determiner name, and date determined.
Field identification is possible by those familiar with heteropteran taxonomy,
and can be accomplished by non-experts who have examined and become
familiar with museum specimens. This species is identified using
characteristics provided in the Species Fact Sheet. Confirmation of field
identifications should be done by taxonomic experts with experience identifying
nabids.
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