Some traits of the biology and epigean behavior of Sisyphus schaefferi (Linnaeus) (Coleoptera: Scarabaeidae: Scarabaeinae: Sisyphini)

A two-year field study on selected traits of the biology of the scarabaeine dung roller Sisyphus schaefferi (Linnaeus) was conducted in a natural park in the western Po Valley in northwestern Italy. Despite laboratory studies carried out over the past few decades, several aspects of the epigean behavior of the species in the wild remain uncertain. Our study revealed that 1) the species is active from early spring to late summer, with reproductive pairs being observed from mid-spring to midsummer; 2) sexual dimorphism in body weight and length is absent; 3) mating individuals are significantly heavier and longer than non-mating individuals; 4) metatibial length increases isometrically with body length and weight; 5) size and weight of the brood balls are isometric with respect to the length and weight of the male of the reproductive pair; 6) brood balls are significantly larger and heavier than food balls, and, whereas brood ball size and weight decrease as air temperature increases, food ball size and weight increase as air humidity rises, but only in non-reproductive periods; 7) pushing and pulling roles are not sex-dependent and can be reversed during the rolling process; 8) combat for balls can involve up to six individuals simultaneously.