Nouvelles larves Pyrénéennes du genre Rhyacophila [Trichoptères]

Abstract

Five new Rhyacophila-larvae from the Department of the Hautes-Pyrénées are described and illustrated. 1. - Rhyacophila relicta McL. ressembles the larvae of Rh. dorsalis and may be distinguished by a darker colour and by the globular shape of the head. 2. - Rhyacophila occidentalis McL. belonging to the Hyperrhyacophilagroup may be distinguished from the closely allied species Rh. evoluta by its general coloration, its white labrum, the shape of its front legs and its pale gill-filaments, generally more numerous. 3. - Rhyacophila mocsaryi tredosensis SCHM., until now unknown in France, is common on the North-pyrenean slope. Its belongs to the Hyperrhyacophila-group and may be differentiated from the two precedent species by the pattern on the head, the appearance of the gills and by the short ventral teeth on the anal claws. 4. - Rhyacophila rupta McL. belongs to the Pararhyacophila-group; it is characterized by long and constricted gill-filaments, by a very short auxillary spine on the anal claws and by the absence of an internal protuberance on the fore trochanter. 5. - The larva of Rhyacophila eatoni McL. belongs to the Hyporhyacophila-group and is characterized by its reddish colour and by its general ressemblance to a Philopotamus. Its difference from the Metarhyacophila-larvae of the allied species, Rhyacophila meyeri, is marked. 6. - Inasmuch as the Pyrenean forms of the Hyper- and Pararhyacophila groups are now known, keys are given for the determination of the last instars. © Masson, 1966.