The Hydropsyche instabilis group (Trichoptera: Hydropsychidae) on the Iberian Peninsula: Evolutionary relationships, new species, taxonomical controversies, and a key to larvae

Abstract

The Hydropsyche instabilis group is a diverse Palearctic group composed of more than 30 species, many of them local endemics. The exact number of species in the Mediterranean Basin remains ambiguous, mainly due to the high variability of the genitalia and the lack of indepth taxonomic studies in some areas. In this paper, we describe the adult male and the larva of a new species from the Iberian Peninsula (Hydropsyche solerorum sp.n.), and provide information about the ecological requirements of the larvae. We also discuss the identity of a species, provisionally designated as Hydropsyche cf. spiritoi. The morphology of the imago genitalia does not allow us to distinguish it from H. spiritoi, but the two forms show some larval morphological differences, molecular divergence at the mtDNA gene cox1, and, apparently, non-overlapping geographical distributions. In addition, we present a complete molecular phylogeny for the mtDNA gene cox1 of the currently known Iberian species of the instabilis group to determine the evolutionary position of H. solerorum, H. cf. spiritoi, and the two other endemic species H. ambigua and H. fontinalis. Finally, we provide an update of the identification key for the known larvae of the genus Hydropsyche on the Iberian Peninsula.