Ohio Mayflies

1.         Anal claw with 6 or fewer conspicuous pointed teeth arising from ventral, concave margin                        (Fig.1.1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

            Anal claw lacking conspicuous pointed teeth on ventral concave margin (Fig.1.2)., or with row             of many tiny spines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

2.         Teeth on anal claw much shorter than claw, dorsal accessory hook present (Fig. 1.3); pronotum             with short, stout seta arising near each ventrolateral margin(Fig. 1.4). . . . . . . . .Nyctiophyax

            Teeth on anal claw almost as long as claw, dorsal accessory hook absent; pronotum lacking             short seta near each ventrolateral margin. . . . . . . . . . . . . Polyplectropus not known in Ohio.

3.         Basal segment of anal proleg approximately same length as distal segment and largely without             setae (Fig. 1.5), concave margin of anal claw with row of tiny spines (Fig. 1.6). Two                         morphologically similar species in Ohio, N. bibimaculatus and N. crepuscularis, (see description             by Ross, 1944). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neureclipsis sp.

            Basal segment of anal proleg distinctly longer than distal segment and bearing many setae,             (Fig. 1.7); concave margin of anal claw lacking tiny spines (Fig. 1.8). . . . . . . . . . . . . . . . . . . 4

4.         Dorsal plate between claw and lateral sclerite of anal proleg with two dark bands fused                         mesally (Fig. 1.9); metanotal and usually mesonotal sa1 setae not more than one-third as long             as longest sa2 setae (Fig. 1.10). . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

            Dorsal plate between claw and lateral sclerite of anal proleg with two dark bands separated             mesally (Fig. 1.11); meso- and metanotal sa1 setae approximately same length as longest sa2             setae (Fig. 1.12). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cyrnellus fraternus

5.         Tarsus of fore leg elongate, about two-thirds as long as fore tibia, anal claw curved                                     approximatey to 90 and anal claw with only one dorsal assessory spine. Mature larvae                         not more than 8 mm in length. Two species in Ohio, C. ohio and C, pallida; both from                         Lake Erie Islands. The nymphs are unknown (Rare). . . . . . . . . . . . . . . . . . . . . . . . . . . Cernotina

            Tarsus of fore leg short, about one-half as long as fore tibia (Fig. 1.13), or tarsus of fore leg             elongate, anal claw not curved as much as 90 . Mature larvae about 10 mm and longer. All             species of nymphs unknown except P. centralis (see Ross, 1944). . . . . . . . Polycentropus sp.