A Revision of the Genus Ephemerella (Ephemeroptera: Ephemerellidae): I. The Subgenus Timpanaga

Abstract

1927–Needham – Ann. Ent. Soc. Amer., 20: 108.1935–Traver – Biol. Mayflies, 565 (hecuba group).1954–Edmunds and Traver – Proc. Ent. Soc. Wash., 56: 238.1954– Demoulin – Bull. Ann. Soc. Ent. Belg., 90: 324.The subgenus Timpanoga of the genus Ephemerella contains but a singIe species,Ephmerella hecuba Eaton. Needham (1927) derived the name for this subgenus from Mt. Timpanogos in north central Utah, after collecting specimens of Ephemerella hecuba in the nearby Provo River. He based the subgenus on the nymph which shows remarkable morphological distinction with its broad entire frontal shelf and its extremely flattened body.