Forensic entomology based seasonal study of decomposition of pig carcasses on and below the ground

Abstract

In the case of buried carcasses, forensic entomologists struggle to precisely estimate the post-burial interval due to a lack of reference data on the entomofauna associated with buried remains and their seasonal variations. The main aim of this study was to compare the decomposition rate, insect arrival and colonization on the pig carcasses above the ground and in graves dug at 40 cm during two seasons. One of the buried carcasses was exhumed frequently while the other was left undisturbed to study the effect of exhumation on the decomposition rate and insect arrival. The faster rate of decomposition was noted in the carcasses above ground as compared to buried ones in both the seasons. Calliphoridae species were amongst the earliest colonizers followed by the Sarcophagidae above the ground in both the seasons. However, their complete absence in the buried environment is noteworthy along with the abundance of Phoridae and Sarcophagidae species. Species from Dermestidae, Cleridae, Histeridae, and Formicidae families were common during both the seasons on the carcass exposed on the surface while in the buried environment Histeridae, Formicidae, and Isopoda species dominated. Seasons and frequent exhumation had a profound effect on the decomposition rate of the carcasses. Real time monitoring of insects and their activities on the carcasses below ground has remained a limitation of the present study but still this research will contribute immensely to a better understanding of decomposition and its investigation.