Impact of Burn Intensity on Decomposition Timeline and Entomofaunal Assemblage in Spring Season

Abstract

Forensic entomologists face several challenges in determining the post-mortem interval (PMI) while dealing with burnt remains. It is important to consider the succession and colonization patterns of insects on such remains while arriving at minimum post-mortem interval (PMImin). The purpose of the present study was to investigate the decomposition rate and insect succession pattern on burnt and unburnt pig carcasses during the spring season (March-May 2022) in a semi-arid region of Haryana with replication in the subsequent year. A total of eight pig carcasses were used during the study, out of which six pig carcasses were burnt at the Crow-Glassman Scale (CGS) level 1, 2, and 3, while two were left unburnt (Control) during both the years. The average accumulated degree days (ADD) for control carcass was estimated 1232.1, while for burnt level 1, 2, and 3 carcasses it was 1392.5, 1524, and 1943.9 respectively. Chrysomya megacephala was the earliest visitor on the control carcasses, whereas Vespa orientalis was the first one to visit on all the burnt carcasses. As the only Indian study focused on burnt carcasses, this study reveals that more severe the burns, the longest is the dry stage and slowest is the decomposition rate. The abundance of coleopterans on burnt carcasses may hold potential value in exploring their effectiveness for estimating an approximate post-mortem interval (PMI).