Ohio Mayflies

The larvae of Pycnopsyche aglona, and P. circularis are not clearly distinguished.

1.         Head setae 13 and 16 broad, blade-like (Fig.1.1); dorsal spacing hump on abdominal segment 1             absent or reduced to remnant occupying no more than about 1/8 of dorsal view (Fig.1.2); case             cylindrical, constructed only of stones. Front of head convex and setae 13 and 16 not close to             arc of spines surrounding frontoclypeus; upper elevation springs seeps and streams. . . . . . . . .             . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche gentilis

            Head setae all hair-like (Fig.1.3); dorsal spacing hump on abdominal segment I present and of             normal size, occupying about 1/4 of dorsal view (Fig.1.4)(often collapsed, deflated, or retracted,             evident only as a wrinkle or pucker); case cylindrical or depressed, constructed of plant                         materials or of sand or stones and often with plant materials. . . . . . . . . . . . . . . . . . . . . . . . 2

2.         Ventral margin of each hind femur with 3 or more major setae (Fig. 1.5). . . . . . . . . . . . . . . . 3

            Ventral margin of each hind femur usually with 2 major setae (Fig. 1.6). . . . . . . . . . . . . . . . 4

3.         Abdominal sternum I with 12-17 anterior (sa1) setae (mostly very small), 6-7 setae on each             posteromesal (sa2) sclerite, and 6-8 setae on each lateral (sa3) sclerite; case depressed in             cross section and with 1 or more long stick along sides; cool springs or streams at higher                         elevations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche divergens

            Abdominal sternum 1 with 3 -11 anterior (sa1) setae (mostly very small), 3-6 setae on each             postermesal (sa2) sclerite, and 20-6 setae on each lateral (sa3) sclerites; case depressed in             cross section and with 1 or more long sticks along sides. . . . . . . . . . Pycnopsyche luculenta

4.         Case mostly mineral:

            in larger streams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche lepida

            or possible spring brooks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche rossi

            or lakes and streams. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche subfasciata

            Case of plant material:

            In small to moderate-sized streams. . . . . . . . . . . . . . . . . . . . . . . . . . Pychnopsyche antica

            In small to medium-sized rivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche guttifera

            Or larger streams and rivers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche lepida

            Or possibly spring brooks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche rossi

            Or cool, moderate-sized streams. . . . . . . . . . . . . . . . . . . . . . . . Pycnopsyche scabripennis

*Ohio EPS does not carry this genus to species. Clearly the safest method to obtain the species of this genus is to rear the nymphs to adults and key them as adults. Morse et al. (2017) do not show figures past step 3.