Taxonomic Review of theCaudatella heterocaudata(McDunnough) andC. hystrix(Traver) Complexes (Insecta: Ephemeroptera: Ephemerellidae)

Abstract

Caudatella columbiella(McDunnough, 1935), new combination, (Insecta: Ephemeroptera: Ephemerellidae) is removed from synonymy withCaudatella heterocaudata(McDunnough, 1929), and a new junior synonym is recognized, based on comparative examination of type material and larval exuviae associated with adults from the type locale ofC. columbiella(=C. californica(Allen and Edmunds, 1961), new status, new synonym).Caudatella circia(Allen and Edmunds, 1961), new status, is recognized as a strict specific synonym ofC. heterocaudata(McDunnough, 1929) (=C. circia(Allen and Edmunds, 1961), new synonym). A neotype is designated forCaudatella hystrix(Traver, 1934), based on a specimen collected in Western Montana, USA, during June 2000. Morphological differences between the type specimen ofC. hystrixand the type specimens of its two junior synonyms,Ephemerella cascadiaAllen and Edmunds, 1961, andE. spinosaMayo, 1952, are detailed. An identification key for larvae of the genusCaudatellais included.