First record of Diamesus osculans (Vigors, 1825) (Coleoptera: Silphidae) colonization on a human corpse.

A partially skeletonized human corpse was found in bushes in Selangor, Malaysia in June 2020. Entomological evidence was collected during the autopsy and sent to the Department of Medical Microbiology and Parasitology, Faculty of Medicine, Universiti Teknologi MARA (UiTM) for minimum postmortem interval (PMImin) analysis. Standard protocols were applied when processing preserved and live insect specimens of both larval and pupal stages. Entomological evidence revealed that the corpse was colonized by Chrysomya nigripes Aubertin, 1932 (Diptera: Calliphoridae) and Diamesus osculans (Vigors, 1825) (Coleoptera: Silphidae). Chrysomya nigripes was chosen as the PMImin indicator as this fly species is an earlier colonizer compared to D. osculans beetle larvae which their presence is the indicative of late stage of decomposition. For the present case, the pupae of C. nigripes were the oldest insect evidence collected and based on the available developmental data, the estimated minimum PMI was established between 9 and 12 days. It is noteworthy to highlight that this is the first record of D. osculans colonization on a human corpse.

Colonization of Rabbit Carcasses by Drain Fly Larvae, Psychoda sp. (Diptera: Psychodidae): The First Report.

INTRODUCTION: Psychoda sp. is often collected from patchy habitats such as sewers, drains and decomposing organic matters. The discovery of Psychoda sp. in forensic studies indicated that it might have noteworthy value in assisting death investigations. PURPOSE: This study reports on the first finding of Psychoda larvae collected from decomposing rabbit carcasses placed in Cameron Highlands, Pahang, Malaysia. METHODS: The larvae were first observed on rabbit carcasses and were collected using tweezers and carefully preserved in 70% ethanol. They were subsequently mounted on microscopy slides using Hoyer's medium and identified as Psychoda sp. morphologically. The identification was also confirmed through a DNA barcoding analysis. RESULTS: Psychoda sp. larvae were collected on day-10 post-mortem where the rabbit carcasses were at the advanced decay stage of decomposition. The cytochrome c oxidase I (COI) gene sequences of the larvae had 90% similarity with the Psychoda spp. in the database. CONCLUSION: The finding of these larvae on carrion may provide additional valuable insights into forensic entomology and may assist in death investigations.