A new species in the Rhyacophila lieftincki Group (Trichoptera: Rhyacophilidae) from southwestern Virginia

Abstract

Members of the Rhyacophila lieftincki Group (Trichoptera: Rhyacophilidae) share distinctive characters in both the adult (Schmid 1970) and larval forms (Smith 1984). In males, segment IX is short ventrally, with the apico-dorsal portion forming a large, usually triangular lobe over segment X. Segment X is somewhat reduced in height, slightly oblique to the base, and bearing small, claw- or toothlike points at its posterior end. Anal sclerites are vestigial or lacking in about half the species, and usually without roots. The phallotheca and endotheca are reduced, and the dorsal appendage of the phallic apparatus is absent. In the larva, the anal proleg has an apicolateral spur that arises independently of the lateral sclerites. The anal claw has a comb-like row of minute teeth ventrally and tergite IX has anterolateral angles extended ventrally to near the sternum.