A comparative analysis of the insect colonisation on sprague dawley carcass at aquatic and terrestrial environments in Shah Alam Selangor

Abstract

Forensic entomology is the use of insect colonisation infesting corpse for the determination of time elapsed since death. The geographic location, weather and other environmental factors contributes a significant impact on the insect colonisation found on the remains. Hence, this study was conducted to determine the types of insect colonisation on Sprague Dawley carcass decomposing on aquatic and terrestrial environments. Three sets of live Sprague Dawley rats were euthanised using cervical dislocation method and placed in a wire cage at aquatic or terrestrial areas. It was observed daily for seven days at varied time intervals (9am, 12pm and 4pm). The insects were collected and preserved with 70% alcohol, recorded and observed under stereo microscope for identification by comparative analysis of morphology. It was observed that the carcasses at the aquatic environment decomposed one day earlier compared to the terrestrial environment. Chrysomya megacephala, Chrysomya rufifacies, Oecophylla smaragdina, Camponotus sp, Monomorium pharaonis, Anoplolepis gracilipes were found dominantly for both terrestrial and aquatic environments, while Porcellio sp. was dominant only in the aquatic environment. As for the larvae determination, only Chrysomya rufifacies larvae species was found dominant in both environments. The findings of this study may help to determine whether the body has been moved from one spot to another. This information will give indication whether the search for a primary or secondary crime scene is warranted during an investigation.