Structure and organization of Scarabaeinae assemblages (Coleoptera, Scarabaeidae) in different vegetation types in Southern Brazil

Patterns of species richness, abundance, diversity, equitability and dominance, and the organization in feeding and behavioral guilds of Scarabaeinae fauna were analyzed in three different vegetation types (forest, native field and crop) in northwestern of Rio Grande do Sul, Brazil, among September and November 2012, with the use of pitfall traps baited with different resources (feces, rotting meat and fermented banana). A total of 9,325 specimens were captured, distributed in nine genera and 32 species. The most abundant species were Onthophagus aff. tristis Harold, 1873, Canthidium aff. trinodosum (Boheman, 1858), Canthon aff. fallax Harold, 1868, Canthon lividus Blanchard, 1845 and Deltochilum morbillosum Burmeister, 1848 which represented 65.54% of the total individuals sampled. The forest showed the highest values of number of individuals and species. The lower richness was observed in the field while the crop showed the lowest abundance of individuals. Scarabaeinae showed qualitative and quantitative differences in their assemblies across vegetation types sampled. The forest showed the highest observed species richness and a fraction of these are unique to this environment, and rarely occurs in other types of ecosystems. In general, the forest has a greater proportion of trophic generalist or copro-necrophagous species in its composition. Another part of this fauna, being largely represented by coprophagous species, is adapted to open environments indicating a change in food guild caused by replacing the forest with pasture. Thus, in a broader context the landscape can play an important role in diversity of dung beetles. © 2015, Fundacao Zoobotanica do Rio Grande do Sul. All rights reserved.