Decomposition and insect succession of pig and rabbit cadavers’ corpses buried in the northern Sudanese zone of Burkina Faso

Abstract

Forensic entomology is a science that studies insects and other arthropods in relation to forensic investigations. This study aimed to examine the presence of insects on pig and rabbit carcasses buried at two different depths, 100 and 50 cm, respectively, along nine sampling dates to establish an insect succession database on buried cadavers in the north sudanian zone of Burkina Faso. In addition, we investigated whether environmental parameters influence both the decomposition of buried corpses and the abundance of insects. Nine pigs and nine rabbits were buried at 100 and 50 cm respectively, at two different sites. Carcasses were exhumed after 14, 28, 42, 56, 70, 84, 98, 112 and 126 days of burial, respectively. Approximately 668 larvae, pupae, cocoons and adults of insects were surveyed on the two substrates during the 2020 and 2021 study periods, divided into 5 main orders, Diptera, Coleoptera, Hymenoptera, Dermaptera and Orthoptera. Accarinae and a few spiders were also inventoried. Succession of insects varied with depth. No significant difference in soil temperature (P = 0.9; 0.12) between the 50 and 100 cm depths was observed. However, significant differences were observed between the temperatures of depths and ambient air (P = 2.3e-07; 0.00027). Necrophagous insects were more abundant on the pig substrate than the rabbit. Our data provided precious information in terms of assessing the postburial interval.