Ohio Mayflies

1.         Most abdominal gills single (Fig. 1.1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

            Most dorsal and ventral gills multiple, lateral gills sometimes single (Fig. 1.2). . . . . . . . . . . . . 4

2.         1 or 2 long sclerite at posterior edge of base of each lateral hump of abdominal segment 1             (Fig. 1.3, Fig. 1.4)); sclerites often only lightly pigmented and difficult to see, but                                     distinguishable by relatively shinier surfaces.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

            No sclerites adjacent to lateral humps on abdominal segment 1 (Fig 1.5). The two species of             Pseudostenophylax, for Ohio, P. sparsus and P. uniformis are not clearly distinguished as                         larvae (Morse, et al., 2017). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pseudostenophylax sp.

3.         Metanotal sa1 sclerites fused (Fig. 1.6); abdominal sternum II with chloride epithelium                         (Fig. 1.7) (in which case abdominal segment IX with only single seta on each side of dorsal             sclerite; case of wood or leaves in irregular outline. . . . . . . . . . . . . . . . Hydatophylax argus

            Metanotal sa1 schlerite not fused although often contiguous (Fig. 1.8), abdominal sternum II             without cholride epithelium and abdominal segment IX with only single seta on each side of             dorsal sclerite (difficult to see); case of twigs, gravel, or leaves, variously shaped, occasionally             3-sided. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Pycnopsyche

4.         Most gills with 2 or 3 branches, none with more than 4 (Fig. 1.9). . . . . . . . . . . . . . . . . . . . 5

            At least some gills with more than 4 branches (Fig. 1.10). . . . . . . . . . . . . . . . . . Ironoquia

5.         Dorsum of head with 2 bands of contrasting color extending from coronal suture to bases of             mandibles and/or narrowed posterior portion of frontoclypeal apotome with 3 light areas: 1                         along each side and 1 at posterior extremity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

            Dorsum of head lacking bands or other well-defined, contrasting areas, usually uniform in color             or with prominent light or dark spots only at points of muscle attachment (Fig. 1.13). . . . . . 10

6.         Dorsum of head with prominent dark bands on light background, lateral bands extended from             coronal suture to base of each mandible, median band on frontoclypeus. . . . . . . . . . . . . . . 7

            Dorsum of head lacking dark bands, but narrowed posterior part of frontoclypeus with 3 light             areas; 1 along each side and 1 at posterior extremity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

7.         Dark dorsal bands on head fussed at junction of coronal and frontoclypeal sutures to form                         U-shaped marking, pronotum with narrow dark band along anterior border and across                         dorsum; case of leaf pieces arranged transversely or longitudinally. . . Nemotaulius hostilis

            Dark dorsal bands on head extended posterad beyond junction of coronal and frontoclypeal             sutures to form V-shaped marking, pronotal markings variable. . . . . . . . . . . . . . . . . . . . . . . 8

8.         Chloride epithelia absent dorsally (as well as dorsolaterally and ventraly) on several abdominal             segments; rough tubular case of wood or leaf fragments, sometimes 3-sided, changed to fine             gravel before pupation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Halesochila taylori (Banks)

            Chloride epithelia absent dorsally (present ventrally and sometimes dorsolaterally). . . . . . . . 9

9.         Chloride epithelia present dorsally, laterally, and verntrally on most abdominal segments; case             of plant and rock materials. . . . . . . . . . . . . . . . . . . . . . . . Asynarchus montanus (Banks)

            Chloride epithelia absent dorsally, may be present dorsolaterally but always present ventrally on             most abdominal segments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Limnephilus (in part)

10.        Pronotum, especially anterior margin, and lateral sclerite of each anal proleg both with short,             stout setae. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Frenesia

            Pronotum usually (Fig. 1.14)(lateral sclerite of anal proleg always) without short, stout setae             (Fig. 1.15). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

11.        Chloride epithelia present dorsally on at least some abdominal segments; case cylindrical, made             of plant materials, sometimes 3-sided. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anabolia sp.

            Chloride epithelia absent dorsally on abdominal segments. . . . . . . . . . . . . . . . . . . . . . . . . 12

12.        Prosternal horn extinding beyond head capsule to mentum of labium; case cylindrical, made of             transverse, narrow, projecting pieces of plant material. . . . . . .. . . . Platycentropus radiatus

            Prosternal horn extending only to distal edge of head capsule (Fig. 1.16); case with wide range             of shapes and materials. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Limnephilus (in part)