Are Dung Beetles Driving Dung-Fly Abundance in Traditional Agricultural Areas in the Amazon? Rodrigo Fagundes Braga, 1 * Vanesca Korasaki, 1 Lı ´via Dorneles Audino, 2 and Julio Louzada 1 * 1 Departamento de Biologia, Universidade Federal de Lavras, Setor de Ecologia CxaPostal 3037, Lavras, MG Cep 37200-000, Brazil; 2 Departamento de Entomologia, Universidade Federal de Lavras, CxaPostal 3037, Lavras, MG Cep 37200-000, Brazil ABSTRACT We evaluated the effects of different land-use sys- tems on the ability of dung beetles to control the population of detritus-feeding flies. We tested the hypotheses that intensification of land use will reduce dung beetles richness, abundance and bio- mass and, consequently, their dung burial ability, affecting the interaction between dung beetles and flies and reducing its effectiveness as a natural biological control. In the Brazilian Amazon we sampled dung beetles, fly larvae and adults; and recorded the rate of dung removal by dung beetles across a gradient of land-use intensity from primary forest, secondary forest, agroforestry, agriculture to pasture. Our results provide evidence that land-use intensification results in a reduction of the richness, abundance and biomass of dung beetles, and this in turn results in lower rates of dung removal in the most simplified systems. We found no significant differences in the abundance of fly larvae between the different systems of land use. However, the number of adult flies differed significantly between land-use systems, presenting higher abundance in those sites with greater intensity of use (pasture and agriculture) and a lower abundance of adult flies in forested systems (primary and secondary forests, and agroforestry). Information-theoretic model selection based on AICc revealed strong support for the influence of land-use systems, dung removal rates and dung beetle abundance, biomass and richness on adult dung-fly abundance. Our results also reveal that dung beetles are not solely responsible for fly control and that other factors linked to land use are influencing the populations of these detritus-feeding insects. Key words: biological control; conservation biology; ecosystem function; habitat change; Scarabaeinae; tropical forest. INTRODUCTION Scarabaeinae dung beetles are known for their great potential to reduce detritus-feeding fly pop- ulations (Hanski 1991; Nichols and others 2008). This biological control process results from com- petition between dung beetles and flies for dung and carrion, because both use this resource for feeding and breeding (Hanski 1991). Dung beetles have both direct and indirect negative effects on flies through exploitative competition and by causing mechanical damage to both eggs and larvae during the dung removal process (Bornemissza 1960; Ridsdill-Smith and Hayles 1990; Bishop and others 2005; Horgan 2005; Nichols and others Received 22 November 2011; accepted 21 June 2012 Author contributions: RFB and JL conceived of or designed study and contributed to adapt the method of sampling. RFB, VK, and LDA per- formed research. VK and JL analyzed data. RFB, VK, LDA, and JL wrote the paper. *Corresponding author; e-mail: rodrigo.fagundes@yahoo.com.br Ecosystems DOI: 10.1007/s10021-012-9576-5 Ó 2012 Springer Science+Business Media, LLC