Leptohyphidae (Insecta, Ephemeroptera) of Amazonas state, Brazil: new records, new combination, new species and identification key for nymphal stages. The following genera of Leptohyphidae occur in the Amazonas state: Amanahyphes Salles & Molineri, Leptohyphes Eaton, Tricorythodes Ulmer and Tricorythopsis Traver. Distribution of Leptohyphidae species in Amazonas state is presented. A new species, Tricorythodes yapekuna sp. nov., is described and can be distinguished from other Tricorythodes by: (1) tarsal claws with pair of submarginal denticles and no marginal denticles; (2) bi-articulated maxillary palp; (3) opercular gill black except on apical margin; (4) gill formula 2/3/3/3/2; and (5) expanded lateral abdominal margin of segments III_VI. The new combination, Tricorythopsis rondoniensis (Dias, Cruz & Ferreira, 2009) comb. nov., is proposed and constitutes the first record of this species in the Amazonas State. An illustrated dichotomous key to identify nymphs of genera and species occurring in the Amazonas State is also presented.
Aquatic insects; Ephemerelloidea; Presidente Figueiredo; Reserva Florestal Ducke
