Karyotype, banding and rDNA FISH in the scarab beetle Anoplotrupes stercorosus (Coleoptera Scarabaeoidea: Geotrupidae). Description and comparative analysis.

Six specimens of Anoplotrupes stercorosus (Coleoptera Scarabaeoidea: Geotrupidae) were analysed using conventional staining, banding techniques and fluorescent in situ hybridization with a ribosomal probe (rDNA FISH). Detailed karyotype description was also joined to a comparative analysis between present data and those previously reported for Thorectes intermedius [Chromosome Res. 7 (1999) 1]. The two species, both belonging to the tribe Geotrupini, show the same modal number but different autosomal morphology which is in contrast with the high chromosome stability argued for Geotrupinae during the last three decades. Moreover, a detailed comparison reveals the occurrence of a plesiomorphic condition in A. stercorosus with respect to the apomorphic one of T. intermedius. This finding agrees with phylogenetic relationships proposed for the two genera based on morphological and anatomical characters.