Chromosomal investigations of eight species of Geotrupidae (Coleoptera, Scarabaeoidea)

– The karyotypes of eight species of Geotrupidae are reported and illustrated. Ceratophyus hoffmannseggi Fairmaire has seven pairs of autosomes and sex chromosomes which are Xy (!), XX ("), while Anoplotrupes stercorosus (Scriba), Geotrupes spiniger Marsham, Sericotrupes niger (Marsham), Thorectes geminatus (Gené), T. intermedius (Costa), T. lusitanicus (Jekel) and Trypocopris vernalis (L.) all have 10 pairs of autosomes and sex chromosomes which are Xy (!), XX ("). In A. stercorosus, G. spiniger and S. niger the autosomes are mainly acrocentric with variously developed centromeric C-bands which in some cases result in heterochromatic short arms, and in A. stercorosus autosome 10 is polymorphic and may have a distinct euchromatic short arm. None of the A. stercorosus autosomes shows any sign of median or submedian centromeres, as suggested by COLOMBA et al. (2004). Thorectes geminatus has autosome 1 metacentric, comparable with that of T. punctatissimus (Chevrolat), but in T. geminatus autosomes 1 and 2 are about the same length while in T. punctatissimus autosome 1 is about 1.5 times the length of autosome 2. Sardinian material of T. intermedius shows some chromosomal polymorphism comparable with that reported by COLOMBA et al. (1996) from mainly Sicilian material. T. lusitanus has six pairs of submetacentric autosomes with heterochromatic short arms while the remaining four pairs of autosomes and the X chromosome are acrocentric. Trypocopris vernalis has autosomes 1 – 8 either metacentric or submetacentric, but C-banding shows that in all these chromosomes one arm is entirely heterochromatic. Résumé.– Les caryotypes de huit espèces de Geotrupidae sont présentés et figurés. Ceratophyus hoffmannseggi Fairmaire a sept paires d’autosomes et des chromosomes sexuels Xy (!) ou XX ("), alors que Anoplotrupes stercorosus (Scriba), Geotrupes spiniger Marsham, Sericotrupes niger (Marsham), Thorectes geminatus (Gené), T. intermedius (Costa), T. lusitanicus (Jekel) et Trypocopris vernalis (L.) ont tous 10 paires d’autosomes et des chromosomes sexuels Xy (!) ou XX ("). Les autosomes sont principalement acrocentriques chez A. stercorosus, G. spiniger et S. niger, avec des bandes C centromériques diversement développées qui dans certains cas constituent des bras courts hétérochromatiques, et chez A. stercorosus l’autosome 10 est polymorphe et peut avoir un bras court euchromatique distinct. Aucun des autosomes de A. stercorosus ne montre de signe de centromère médian ou submédian, contrairement à ce qu’ont suggéré COLOMBA et al. (2004). L’autosome 1 de Thorectes geminatus est métacentrique, comparable à celui de T. punctatissimus