Factors Associated with the Occurrence, Potential Distribution and Conservation of Anoxia orientalis (Coleoptera, Scarabaeidae) at Different Spatial Scales

Anoxia (Protanoxia) orientalis is a beetle of the family Melolonthidae for which Italy represents the western limit of its distribution. The ecology of this species is little known from the quantitative point of view. The ecological correlates of A. orientalis presence in the whole European range and, more specifically, at its western border in Sicily, are analyzed in this paper to develop a potential distribution map for Sicily and to define the habitat selection of this species. There was a clear non-random habitat selection by A. orientalis at both the European and the Sicilian scales and a clear difference in the factors affecting the presence of this species in the larger spatial scale compared to Sicily. At the European scale, the bioclimatic factors were more important than landscape factors, whereas the same was not true at the Sicilian scale. In Sicily, the populations were statistically influenced by a combination of predictors that make their potential optimal distribution very narrow and mostly limited to a few coastal areas, suggesting a region-specific ecological diversification. Since A. orientalis is in strong decline in Italy due to the degradation of coastal environments, it is necessary to minimize the degradation of the dune and back dune environments in Sicily to achieve better management for the populations of this beetle species.