Abstract
Thirteen species in 3 genera of dung beetles (Scarabaidae), Aphodius rectus, A. sordidus, A. languidulus, A. pusillus, A. haroldianus, A nigerrimus, A. haemorrhoidalis, A brachysomus, A. rygosostriatus, A. pratenisis, A. sublimbatus, Caccobius jessoensis and Liatongus phanaeoides, were collected from cattle dung in grazing pastures at 8 sites in the Tokachi district in eastern Hokkaido in 1977. The sites chosen were Obihiro, Tokachi-Shimizu, Shihoro, Sarabetsu, Hiroo, Obitomi, Tokachi-Chokubetsu and Ashoro. Number of species in collected beetles increased in proportion as the mean temperature (from May to October) of the sites was high. Based on the results of seasonal prevalence in Obihiro in 1979, 1980, 1981, 1988 and 1993, besides the fact that the numbers of A. brachysomus, a dominant species in western Hokkaido, were low in the Tokachi district, the species composition and seasonal prevalence of the dung beetles collected in these two regions were not significantly different. On the other hand, many differences were found between the species composition and seasonal prevalence of dung beetles collected in the above-mentioned regions and those collected in the middle and southwest areas of Japan. In Tokachi district, A. rectus, A. sordidus, and A. pusillus were regarded as main dwellers and A. haroldianus and C. jessoensis as main tunnelers. Seasonal prevalence of dung beetles in Tokachi district was divided into the following three types: uni-voltine type, A. sordidus, A. haroldianus, A. heamorrhoidalis, A. pratenisis, A. sublinbatus and L. phanaeoides; bi-voltine type, A. rectus and A. pusillus, and an all-season type, C. jessoensis.
