Post-mortem interval determinations using insects collected from illegally hunted and dehorned rhinoceros in the Republic of South Africa from 2014 to 2021.

Abstract

Wildlife forensic science is a growing research field globally with application in criminal cases of illegal hunting requiring an estimate of time of death based on insect fauna. The techniques and procedures of forensic entomology acquired over the last 40 years, used in legal cases relating to human remains, can be adapted to decomposing wildlife. Research on carrion utilising the rate of development of insect immatures provides a biological clock from which a minimum post-mortem interval (minPMI) can be derived. The following study concerns 19 rhinoceros that were illegally killed and dehorned in the Republic of South Africa between 2014 and 2021. The paper details 74 samples of insect evidence collected from these rhinoceros remains from which an accurate estimate of their PMI was calculated. The specimens comprised 18 species from 12 families belonging to three insect orders. Many Dipteran and Coleopteran species were found on and around each carcass. The species of fly larvae (family Calliphoridae) used in each case to estimate the PMI are as follows: Chrysomya marginalis (Wiedemann) (13 cases), Chrysomya chloropyga (Wiedemann) (2 cases), Chrysomya albiceps (Wiedemann) (1 case) and Chrysomya megacephala (Fabricius) (1 case). Two species of Coleoptera from the family Dermestidae and Silphidae involved Dermestes maculatus (DeGeer) and Thanatophilus micans (Fabricius), respectively, also were involved in one PMI estimation each. The paper highlights opportunities for improving our global understanding of gaps in procedures and training related to wildlife criminal cases.