The pupal exuviae of Chironomus crassimanus Strenzke (Díptera: Chironomidae), an acid-resistant species from Germany

摘要

The first descriptions of the pupal exuviae of Chironomus crassimanus Strenzke, 1959 were based on mixed populations of Chironomus which did not allow a proper recognition of their features in the available taxonomical keys. This paper describes the morphological characteristics of Ch. crassimanus based on laboratory-reared specimens. A more comprehensive description is ensued and ecological information on the species is also provided. Species of the genus Chironomus Meigen, 1803 are distributed in all zoogeographical regions except Antarctica (Ashe 1983) and have been reported in extremely acidic ecosystems (Rodrigues 2001, Rodrigues & Scharf 2001). Chironomus comprise several hundred species, some of which are discernible only on cytological characters (Correia & Trivinho-Strixino 2007). More than 50 valid European species of Chironomus have been described so far (Fittkau & Reiss 1978, Lindeberg & Wiederholm 1979, Vallenduuk & Moller Pillot 1999), but the taxonomic descriptions have been mostly based on features of the imaginai and larval stages alone, so that few studies have aimed at an in-depth description of their pupae/exuviae (but see Langton 1991).