Identification of families of aquatic insects

Ephemeroptera
 Characteristics
 Wing pads
 1 claw on each leg (contrast
with Plecoptera)
 2-3 terminal segmented
filaments (cerci) on
abdomen
 Usually with lateral
abdominal gills
Baetidae
 Characteristics
 Small and streamlined (A)
 Antennae usually 2-3 times
longer than head’s width (B)
 Hind wing pads sometimes
absent or minute (C)
 Oval or heart-shaped gills on
abdominal segments (D)
 Posterior abdominal segments
usually lacking spines pointing
backwards (E)
Ephemerellidae
 Characteristics
 Mandibles without tusks (B)
 Forelegs without
conspicuous hair fringes (C)
 Gills absent from 2nd
abdominal segment (D)
Heptageniidae
 Characteristics
 Flattened body with
outspread legs (B)
 Claws (black arrow) shorter
than tarsi (white arrow) (C)
 Head with horizontal
orientation (D)
 Gills on abdominal
segments 2-5 usually platelike with basal tufts or flaps
(E)
Leptohyphidae
 Characteristics
 Operculate gills on
abdominal segment 2
rounded or triangular; gill
lamellae on segments 3-6
simple or bilobed without
fringed margins (B)
Leptophlebiidae
 Characteristics
 Gills on segments 2-5 forked
and in tufts with fringed
margins, or double lamellae
ending in filaments or
points (B)
 Apicolateral margin of
maxillae with dense brush
of hairs (C)
 Claws on all legs similar in
appearance (D)
Plecoptera
 Characteristics
 Wing pads
 2 claws on each leg (contrast
with Ephemeroptera)
 2 cerci
 No lateral abdominal gills
Perlidae
 Characteristics
 Labium with single slit
dividing it into two distally
rounded lobes (B)
 Glossae (white arrow)
shorter than paraglossae
(black arrow) (C)
 No gills on abdomen (D)
 Branched gills on thorax (E)
Perlodidae
 Characteristics
 Usually elongate with
cylindrical body; often with
distinctive color patterns on
dorsal surface (A)
 Glossae (white arrow) shorter
than paraglossae (black arrow)
(B)
 No branched gills but perhaps
single gills in thoracic region
(C)
 Cerci as long or longer than
abdomen (D)
Pteronarcyidae
 Characteristics
 Head with somewhat
vertical orientation, tipped
down when insect resting
flat (A)
 Bushy gills on both thoracic
segments (black arrow) and
abdominal segments 1-2 or
1-3 (white arrow) (B)
Trichoptera
 Characteristics
 No wing pads (contrast with
Ephemeroptera and
Plecoptera)
 3 pairs of jointed legs on
thorax (contrast with
Diptera)
 1 pair of terminal abdominal
prolegs (contrast with
Lepidoptera and larval
Coleoptera)
 Often in cases
Brachycentridae
 Characteristics
 First abdominal segment
lacking any humps; second
thoracic segment with
connecting plates (B)
 4-sided case tapering to
posterior end (C)
 Tibia with line of stout
spines (E)
Glossosomatidae
 Characteristics
 Thoracic segments 2 and 3
usually fleshy or with small
separated plates (B)
 Basal portion of anal claw
broadly joined to abdomen;
anal claw hook-shaped and
bearing at least 1 accessory
hook (C)
 Abdominal segment 9 with
sclerite on dorsum (E)
Hydropsychidae
 Characteristics
 Abdomen with ventrolateral
rows of branched gills (B)
 Brush of hairs (black arrow)
at base of hook-shaped anal
claw (white arrow) (C)
 3 thoracic segments all with
sclerotized dorsal plates (D)
Hydroptilidae
 Characteristics
 Sclerotized plates on all 3
thoracic segments (B)
 Abdomen lacking
ventrolateral gills (C)
 Usually with 2-3 hairs at
base of anal claw (D)
Diptera
 Characteristics
 No jointed legs on thorax,
some with prolegs on
prothorax (contrast with
Trichoptera, larval
Coleoptera and
Lepidoptera)
 Very diverse group
Athericidae
 Characteristics
 Abdominal segments
containing ventral pairs of
prolegs bearing crochets (B &
C)
 Terminal processes longer than
terminal prolegs and with
distinctive hairs on them (D)
 Head capsule well-developed
dorsally with sclerotized
portions sometimes exposed
(E)
Chironomidae
 Characteristics
 Sclerotized head separated
from thorax; body with pair
of prolegs on prothorax
(black arrow) (B)
 Pair of terminal prolegs (C)
 Thorax and abdomen about
equal in diameter (D)
Simuliidae
 Characteristics
 Fan-like mouth brushes (B)
 Prothorax with ventral
median proleg (C)
 Abdomen usually swollen
posteriorly (D)
 Posterior segment of
abdomen ending with ring
of radiating rows of minute
hooks (E)
Tipulidae
 Characteristics
 Head usually partially
retracted into thorax (B)
 Spiracular disc on end of
abdomen surrounded by 1-3
or 5-7 variously developed
lobes often fringed with
hairs (C & D)
Coleoptera
 Characteristics
 Adults


First pair of wings hardened to form
nonoverlapping shell-like covering
(elytra) over abdomen (contrast with
adult Hemiptera)
Chewing mouthparts
 Larvae
 3 pairs of jointed legs on thorax
(contrast with Diptera)
 No terminal abdominal prolegs
(contrast with Trichoptera)
Elmidae
 Characteristics
 Adult
 Filiform antennae much
longer that head (B)
 Tarsi 5-segmented (C)
 No swimming hairs on hind
legs (D)
Elmidae
 Characteristics
 Larvae
 Tarsi containing 1 claw
(white arrow) (B)
 Abdomen lacking gills (C)
 Abdominal segment 9
bearing ventral operculum
(D)
Hemiptera
 Characteristics
 First pair of wings with
hardened base and
overlapping membranous
apical portion (contrast with
adult Coleoptera)
 Sucking/piercing
mouthparts forming long
jointed beak (contrast with
larval Coleoptera and
Odonata)
Corixidae
 Characteristics
 Short front legs modified
into scoop-shaped
structures (B)
 Hind legs oar-like with
swimming hairs (C)
 1-segmented, short
triangular beak (E)
Veliidae
 Characteristics
 Antennae longer than head
(B)
 Hind femur not extended
past end of abdomen (D)
Lepidoptera
 Characteristics
 3 pairs of jointed legs on
thorax (contrast with
Diptera)
 At least 2 pairs of abdominal
prolegs terminating in circle
of hooklets (crochets)
(contrast with Trichoptera
and larval Coleoptera)
Pyralidae
 Characteristics
 Prolegs on abdominal
segments 3-6 and 10 with
crochets (B & C)