1. Abdomen usuallly with some color patterning (Fig.1.1), at least with longitudinal markings on some sterna, not appearing somewhat flattened and broadened; caudal filaments half or less length of body; wingpads with or without various dark spotting. . . . . . . . . . . . . . . 2
Abdoman essentially lacking color patterning or dark markings (Fig.1.2), appearing somewhat flattened and broadened; caudal filliments more than half length of body; wingpads with dark markings. . . . . . . . . . . . . . . . . . . . . . . . . . . Ephemera guttulata
2. Hindwingpads and forewingpads with dark markings (Fig.1.3). . . . Ephemera simulans [Note: Wingpad spotting is usually apparent to at least some degree beginning in middle-instar larvae and more apparent in late instars. Spotting should not be confused with dark margining of veins that is sometimes apparent in relatively mature larvae of several species]
Hindwingpads without dark spotting (Fig.1.4). . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Forewingpads with dark spotting (Fig.1.5). . . . . . . . . . . . . . . . . . . . . . Ephemera varia
Forwingpads without dark spotting, but sometimes some diffuse blotching apparent. . . . . . (Fig. 1.4). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ephemera blanda
Key to Ohio Ephemera Nymph Species
