Decomposition of buried rabbits and pattern succession of insect arrival on buried carcasses

Forensic entomology is the field of research that applies the biology of insects to criminal investigations. This study, which used rabbits as experimental models, was carried out in Al-Riaydh, Saudi Arabia, to gather data on forensically important insects and their succession and decomposition on decaying buried carcasses at two depths during two periods: the first period lasted from January 28-May 30, 2021 (winter-spring), and the second period was from September 5, 2021, to January 4, 2022 (summer-onset winter). Decomposition was seen in three stages during the first period (bloated, decay, and drying) and two stages during the second period (decay and drying). Temperature, humidity, and depth of burial influenced the stages of carcass decomposition and abundance of insects. Eleven species from the Diptera order, encompassing five families (Calliphoridae, Sarcophagidae, Muscidae, Phoridae, and Ulidiidae), were identified. Additionally, four species from the Coleoptera order were recorded, representing four families (Dermestidae, Tenebrionidae, Histeridae, and Nitidulidae). During the first period of the study, all species were identified at a depth of 20 cm (16 species), while, at a depth of 40 cm, nine types of them were detected. In the second period, only one species of beetle was observed at 20 cm, whereas there were only four fly species present. Furthermore, at a depth of 40 cm, only one species of fly was discovered throughout the entire period. The identified insect species can function as reliable forensic indicators, aiding in PMI estimation and enhancing the overall precision of forensic investigations. These results indicate that these insects are significant in carcass decay and therefore forensically important.