Plecoptera Families

I. Plecoptera - Stoneflies

A. Adults

1. Membranous wings without many cross veins
2. Wings held folded, flat on back
3. Wings dissimilar in size and shape; hind wings larger with anal lobe that is folded at rest
4. Tarsi 3-segmented
5. Long, many segmented antennae
6. Chewing mouthparts

B. Nymphs

1. Aquatic
2. 3 pairs of segmented thoracic legs
3. Compound eyes
4. Wings developing in fixed pads
5. Chewing mouthparts
6. Labium not extensible or folded back on itself
7. Tarsi with 2 claws
8. Abdomen always ending in 2 filaments (cerci)
9. Gills on center of thorax; maybe fingerlike or tufts of filaments; may also occur on mandibles, base of legs, or first few abdominal segments

II. Adults

A. Family: Pteronarcyidae (Giant Stoneflies)

1. Labium with glossae and paraglossae of approximately same length and size and set at same level
2. Gill remnants on sides of thorax
3. Gill remnants also on sides of abdominal segments 1 and 2, sometimes 3

B. Family: Taeniopterygidae (Winter Stoneflies)

1. Labium with glossae and paraglossae of approximately same length and size and set at same level
2. No gill remnants on sides of thorax
3. 2nd segment of tarsus approximately same length as 1st

C. Family: Perlidae (Common Stoneflies)

1. Labium with glossae much reduced and set below paraglossae
2. Remnants of branched gills on thorax