Seasonality and bait type driving the diversity of dung beetle (Scarabaeidae: Scarabaeinae) communities in urban remnants of the Atlantic Forest

Abstract

Describing dung beetle communities in tropical forest remnants located in disturbed/urbanized and conserved areas can provide information about the functioning of these ecosystems and support conservation plans. This study aimed to verify the effect of seasons and bait type on dung beetle communities in remnants of the Atlantic Forest in order to describe their composition and diversity parameters. The study was carried out during both the rainy and dry seasons in periurban and urban remnants. Eighteen pitfall traps baited with feces, carrion, and injured millipedes were established in each site. A total of 3501 individuals and 23 species were recorded. Urban remnant presented higher abundance of individuals in the dry season. On the other hand, in periurban remnant the higher abundance was verified in the rainy season. The diversity was higher in the rainy season in both sites. In urban remnant, Coprophanaeus ensifer was found to be generalist regarding its choice of bait (feces and carrion). The use of injured millipedes as bait allowed the record of the predatory species Deltochilum alpercata. Among the types of bait used, the injured millipedes proved to be very effective, capturing a greater diversity of dung beetles during the rainy season in both remnants, and allowed the collection of specialized, necrophages, and generalists species. Therefore, we propose the use of mixed-bait sampling designs in inventories and surveys to increase the chances of sampling species with different traits or dietary preferences, which are often rare in collections.