Effects of bait type and seasonal temperature variation on the attraction of sarcosaprophagous flies in a Brazilian Cerrado

Abstract Organic matter decomposition is an important ecological process for nutrient cycling, and sarcosaprophagous flies play a key role in this process. However, assemblage composition varies according to the substrate type, the environment and environmental conditions. This study evaluated the effects of bait type and seasonal temperature variation on the abundance and species richness of Calliphoridae and Sarcophagidae in a Brazilian Cerrado area. The insects were collected in PET bottles traps containing 100 g of decomposing baits - bovine liver, chicken viscera or fish previously exposed for 24 h at environmental temperature, and deployed in an experimental area at the Federal Institute of Maranhão between March and August 2022. A total of 6502 individuals belonging to 33 species were collected. Sarcophagidae showed higher richness (27 spp.) compared to Calliphoridae (6 spp.). Chrysomya albiceps , Chrysomya megacephala , Chloroprocta idiodea , Cochliomyia macellaria , and Lucilia eximia (Calliphoridae), as well as Oxysarcodexia thornax (Sarcophagidae), were the most abundant species. Fish and chicken viscera were the most attractive baits, yielding the highest abundance of individuals, while Calliphoridae richness was highest in fish and chicken baits and Sarcophagidae richness in bovine bait. In addition, the temporal variation of temperature affects the abundance and richness of fly assemblages in Cerrado environments, possibly reflecting reduced adult activity or faster bait desiccation during warmer periods. Our findings indicate that bait type and seasonal temperature variation may influence the abundance and species richness of Calliphoridae and Sarcophagidae in the Cerrado. Implications for insect conservation The sensitivity of these decomposers to seasonal temperature fluctuations suggests that they may respond to future climatic changes. Furthermore, our results indicate that animal proteins are effective attractants for the short-term monitoring of dipteran biodiversity in tropical savannas, providing baseline data that may contribute to future assessments of ecosystem condition and nutrient cycling.