A checklist of forensically important insect taxa on decomposing carcasses and successional patterns related to decomposition and season in Minnesota.

Abstract

Numerous studies in North America have focused on the entomofauna associated with decomposing pig carcasses. However, research is lacking in the upper Midwest region of the United States. This study establishes a reference checklist of forensically important insect taxa throughout stages of decomposition of a carcass and investigates these taxa in relation to both stage of decomposition and season in Minnesota. Eleven pig carcasses (Sus scrofa) were placed in the field at monthly intervals from May 2017 through September 2018 and were examined daily to collect both immature and adult insects. Collections were with aerial net, pitfall traps, and hand collection. Adult specimens were identified and preserved. A portion of calliphorid larvae were also reared to adult in the laboratory for identification and preservation. In total, 64 forensically important insect taxa were recorded, representing 14 families, and including 12 species of Calliphoridae. Phormia regina and Lucilia sericata were consistently abundant through temperate seasons. Calliphoridae dominated the early stages of decomposition, and Coleoptera increased in the later stages of decomposition. The results of this study will serve as a practical tool of geographic reference of forensically important insects for local law enforcement agencies and forensic entomologists investigating cases of unnatural death in Minnesota, and also will serve as a foundation for further succession research in the region.