New developmental data for Cynomya mortuorum (L., 1761) in Belgium (Diptera: Calliphoridae).

The calliphorid Cynomya mortuorum (L., 1761) is a forensically important species mainly found in the Palearctic region. Knowledge about its biology and ecology is scarce. Thermal constants as well as developmental time were studied at constant and variable regimes of 5 average temperatures: 14, 16, 18, 20 and 22°C, respectively. Total developmental time varied between 15.82±0.40 days at 22°C and 28.67±2.38 days at 14°C, for the constant regime, and between 16.05±0.67 days at 22°C and 32.79±1.77 days at 14°C, for the variable regime. No significant differences were observed between ADD, and threshold at the constant (ADD: 277.39±14.78 DD; lower threshold: 4.72°C) and variable regimes (275.99±14.16 DD; lower threshold: 5.05°C).

Cadaveric volatile organic compounds released by decaying pig carcasses (Sus domesticus L.) in different biotopes.

Forensic entomology uses pig carcasses to surrogate human decomposition and to investigate the entomofaunal colonization. Insects communicate with their environment through the use of chemical mediators, which in the case of necrophagous insects, may consist in the cadaveric volatile organic compounds (VOCs) released by the corpse under decomposition. Previous studies have focused on cadaveric VOCs released from human corpses. Nevertheless, studies on human corpses are restricted for many reasons, including ethics. Forensic entomologists use pig as animal model but very few information are available about the decompositional VOCs released by a decaying pig carcass. We here tested a passive sampling technique, the Radiello diffusive sampler, to monitor the cadaveric VOCs released by decomposing pig carcasses in three biotopes (crop field, forest, urban site). A total of 104 chemical compounds, exclusively produced by the decompositional process, were identified by thermal desorption interfaced with gas chromatography and mass spectrometry (TDS-GC-MS). Ninety, 85 and 57 cadaveric VOCs were identified on pig carcasses laying on the agricultural site, the forest biotope and in the urban site, respectively. The main cadaveric VOCs are acids, cyclic hydrocarbons, oxygenated compounds, sulfur and nitrogen compounds. A better knowledge of the smell of death and their volatile constituents may have many applications in forensic sciences.