Seasonal diversity and dynamics of entomofauna associated with the decomposition of pig (Sus scrofa domesticus L.) carcasses in a Peri-urban area of Central Burkina Faso, West Africa.

Abstract

This study aimed to determine the effects of seasons on the diversity and dynamics of insects associated with pig carrion in Gampela, Plateau Central Region, Burkina Faso, West Africa. Pig carcasses (Sus scrofa domesticus L.) were exposed in an open area to monitor their decomposition process and their colonization by insects during a warm and dry period (March-April 2015), a warm and wet period (August-September 2015) and a cool and dry period (December 2015-January 2016). Monitoring and entomological data collection occurred for 60days for each study period. The decomposition process always included five stages (fresh, bloating, putrefaction, postputrefaction, and skeletal), which varied in duration depending on the study period. In sum, 118,761 insects belonging to 4 orders, 12 families, 17 genera, and 21 species were collected during the three study periods, with approximately 61% of the individuals collected during the warm and wet period. The dynamics of insect populations associated with the pig carcasses included two peaks at each study period. Formicidae was the most abundant insect family in each study period, but Musca domestica was the most abundant species. The listed species were found to belong to four trophic groups with a predominance of predators/carnivores followed by necrophagous insects. The orders, families, and trophic groups reported in this study were significantly more abundant during the warm and wet period. The results show prospects for the use of Calliphoridae, Muscidae, and Dermestidae in criminal investigations, depending on seasonal variations in Sudano-Sahelian areas.