Preimaginal feeding habits of isoperla carbonaria aubert, 1953 (Plecoptera: Perlodidae)

Feeding habits of larval Isoperla carbonaria Aubert, 1953 have been investigated in the Rio Alpetto, an Alpine creek of northwestern Italy. This species is characterised by relatively small size and rheophilous habits, and inhabits streams above 350 m a.s.l. in the Alps, Apennines and Sicily. In this study, we analysed the gut contents of 72 larvae of this species, with the aim of investigating feeding preferences and to assessing the existence of size-related shifts in the trophic spectrum. Larvae were collected from a single reach, whose benthic coenosis was also determined. We detected evident trophic preferences in the diet: few taxa constituted the greatest part of the ingested items, independently from their availability in the substratum. Moreover, we observed that largest larvae fed on a broader number of taxa. These findings are discussed and compared with data obtained from other Systellognatha species.