Flathead Mayfly (Heptageniidae)

Head and body flattened; eyes and antennae on top of head (not side)

Brushlegged Mayfly (Isonychiidae)

First set of legs with a dense row of hair along the inner surface

Small Minnow Mayfly (Baetidae)

Middle tail short or lacking, lacks hairs on front two legs, head and body not flattened

Prong-gilled Mayfly

Gills pronged or forked, middle tail same length as others, no hairs on front legs, body and head not flattned

Spiny Crawler Mayfly (Ephemerellidae)

Gills absent from abdominal segments 1 and 2, and sometimes 3, gills round, oval, or hear shaped (not forked), middle tail the same length as the others, no hairs on inside front arms, head and body not flattened

Giant Stonefly (Pteronarcyidae)

Tufted, filamentous gills at base of legs, on ventral (bellyside) of thorax, and on ventral abdomen segments 1 & 2 ("Manly Man")

Nemourid Stonefly (Nemouridae)

Tufted gills present only on neck

Common Stonefly (Perlidae)

Tufted, filamenouts fills only at base of legs ("Hairy Armpits")

Large Winter Stonefly (Taeniopterygidae)

Telescoping gills at the base of each leg

Gills absent from thorax of stonefly?

PRESERVE IT!

(too difficult to ID to family in the field)

Unknown Mayfly?

Gills present on abdominal segments 1-3, or opercualte gills (larger harder gill coverings)

Preserve it!  

Snail case maker (Heliocopsychidae)

Case is like a snail shell, coiled up

Micro Case Maker

Case is tiny and purse-like, composed of sand or silt, caddisfly has three hardened plates on thoracic segments and no gills on abdomen

Saddle case maker (Glossosomatidae)

Case is a dome of rocks that covers larva like a turtle shell; the head and end of the abdomen are visible underneath (the bottom of the bug sticks out)

Casemaker

If it not coiled like a hose, is a micro caddisfly (case made of fine sand and silt), or the case covers the caddisfly like a turtle shell..

Preserve it!  

(most casemakers cannot be identified by their cases alone)

Netspinner Caddisfly (Hydropsychidae)

Gills on abdomen ("Fuzzy Belly"); all three segements of the thoraz are coverd by hardened plates

Fingernet Caddisfly (Philopotamidae)

No gills on abdomen; head is brigh orange and body is bright yellow; only first segment of thorax is covered by a hardened plate

Unknown Caddisfly

Not in a case, no gills on abdomen, body is not bright yellow

Preserve it!

A few families of caddisflies can be difficult to ID in the field, preserve them if you are unsure of what it is

Long Toed Beetle (Dryopid)

Short, thick antennae that are usually not visible

Riffle Beetle Adult (Elmidae)

Visibile antennae that are longer than the head

Waterpenny Beetle (Psephinidae)

Round, flat shell that vocers the beetle

Riffle Beetle Larvae (Elmidae)

Abdominal segment 9 (last one) with tufted gills and has an operculum (hardened cover that can close over the gills like a cargo plane door)

Ptilodactylidae Beetle 

Abdominal segment 9 (last one) with tufted gills and

NO OPERCULUM (hardened cover that can close over the gills like a cargo plane door)

These tend to be lighter in color

Cranefly (Tipulidae)

Grub-like body; leathery skin with welts; no pro-legs, last abdominal segment with hairs/projections; head usually not visible

Blackfly (Simuliidae)

Pro-legs on first segment of thorax; body like a bowling pin

Midge (Chironomidae)

Pro-legs on first segment of thorax and last segment of abdomen; body segmented, squishy and small

Biting Midge (Ceratopogonidae)

NO pro-legs; body segmented, squishy and small, head is visible

Unknown Trueflies

Does not have a visible head, may have prolegs, does not have hairs/projections at the end

Preserve it!

Some trueflies that are not craneflies, blackflies, midges, or biting midges are hard to ID in the field

Crayfish (Cambaridae)

Large pinching claws; scoots/swims backwards

Scud 

MUST PRESERVE ALL SCUDS

You cannot ID a scud to family level in the field, please preserve ALL scuds

Sowbug (Asellidae)

Same (or similar) length legs; flat body; curls up or crawls on bottom

Clubtail Dragonfly (Gomphidae)

Thirs segments of antennae ar much larger than other segments (might look like pinchers)

Darner Dragonfly (Ashnidae)

Lower jaw is flat when viewed from the side,

third segments of antennae are the same as the others

Unknown Dragonfly

Lower jaw is rounded like a scoop when viewed from the side, third segments of antennae are the same as the others

Broadwinged Damselfly

First segments of antennae are as longas, or longer than the other segments combined

Narrowwinged (Coenagrionidae)

All segments of antennae are about the same length antennae are thin, lower jaw tapers slowly; not greatly narrowed

Spreadwinged (Lestidae)

Lower jaw is long and narrow when viewed from underneath, all segments of antennae are about the same length, antennae are thin

Asian Clam (Corbiculidae)

Ridges are visible and can be felt on the shell

Pea Clam (Spherridae)

Ridges are barely visible and cannot be felt, usually very small clam

Planorbidae (Lunged Snail)

Shell is coilded on one plane like a hose

Gilled Snail

Opening is on the right when the apex (pointy end) is up

Preserve 

Lunged Snail

Opening is on the left when the apex (pointy end) is up

Preserve