Michele Luzzatto

A study of a dung beetles (Coleoptera: Scarabaeidae) taxocoenosis from a xeric area of the Southern Cone of South America has been carried out in Dec 1987and Febr 1989. 13 spp.  were detected belonging to 4 tribes. The phyletic and geographic relationships of the involved taza suggest at least 2 different Distribution Patterns overlap in the study area. The trophic and behavioural features of the different taza have been analyzed in relation to their position in the taxocoenosos and interpreted from a causal point of view also on the ground of their biogeographical history

Food relocation in dung beetles consists in the removal of dung fragments from a source and their burial before use. Such behaviour is generally understood as an adaptive response to the degradation of food at the ground surface and to competition among coprophagous insects. We investigated the feeding behaviour of the Eucraniina in a xeric environment.New data on food preference, transportation behaviour, and the structure of the feeding burrow of these insects is presented. The food relocation behaviour of the Eucraniina strongly differs from all previously described patterns and seems to be exclusive to this subtribe.It is suggested that in the Eucraniina food relocation can be interpreted as a behavioural strategy to exploit an otherwise useless food source, by rehydrating it in hypogeal conditions. This hypothesis is supported by the properties of utilized food and the characteristics of a xeric environment.