The use of ventral sclerites in the taxonomy of larval hydropsychids

Abstract

The use of the ventral posterior prosternites by STATZNER (1976) as a character to separate larvae of Hydropsyche angustipennis CURTIS and H. pellucidula CURTIS is noted and this paper considers its significance in relation to hydropsychid taxonomy. Larvae of the following British species have been examined and the appearance of the posterior prosternites described: Cheumatopsyche lepida PICTET, Diplectrona felix McLACHLAN, H. pellucidula, H. angustipennis, H. siltalai DÖHLER, H. contubernalis McLACHLAN, H. fuluipes CURTIS, H. instabilis CURTIS. It is suggested that key characters such as sclerite shape are preferable to more variable head pattern markings. The separation of H. angustipennis and H. pellucidula larvae by use of posterior prosternite shape is confirmed for British material. In addition, this character may be used to distinguish H. fuluipes from H. instabilis. (At present they are separated on head markings — HILDREW & MORGAN, 1974). As a further demonstration of the use of sclerite characters in larval hydropsychid taxonomy, a key is given to the eight species described by HILDREW & MORGAN.