|Publication Type:||Journal Article|
|Year of Publication:||1996|
|Authors:||C. G. Walsh, Gandolfo D.|
Paracoprid scarabs (Scarabaeidae: Scarabaeinae) dig tunnels under or near various animals droppings, portions of which the beetles store to feed on or use to build nests for their larvae. These nests have been classified into 3 main patterns, based mainly on the structure of the nest, egg cell, and the existence of parental care. Pattern I nests are simple accumulations of feces at the end of a burrow, known as brood masses, with 1 or several eggs in individual cells built into the dung. Pattern II nests consist of spheroidal or pear-shaped food provisions plastered with a layer of soil (brood balls) loose in a subterranean chamber. Pattern III nests have several brood balls in one large chamber and receive parental care. The construction process of the brood masses and brood balls of 13 species of laboratory reared paracoprids from Argentina was studied by analyzing different stages of their construction. The species Dichotomius anaglypticus (Mannerheim), D. haroldi (Waterhouse), D. micans (Luederwaldt), D. semiaeneus (Germar), Onthophagus hirculus Mannerheim, Oruscatus davus (Erichson), and Gromphas lacordairei Brulle belong to the pattern I; Sulcophanaeus batesi (Harold), Sulcophanaeus menelas (Castelnau), S. imperator (Chevrolat), Bolbites onitoides Harold, Ontherus sulcator (F.), and O. appendiculatus (Mannerheim) to pattern II. The last pattern, which includes the Phanaeina, some Dichotomina (both subtribes of Coprini), and the Old World Catharsius, entails at least 4 different construction processes. Most brood masses and balls studied in this work are described for the first time. The building of spheroidal brood balls loose in a chamber could have evolved at least four times from the primitive brood masses, through four different convergent processes.