The temperature effect on the cuticular chemical profile of Lucilia sericata blowfly larvae

Forensic entomology has become increasingly important in the last decade. In cases of homicide, suicide or suspicious death, insect specimens are taken into consideration as acceptable evidence like blood, fingerprint or any other biological materials. When solving criminal cases, it is essential to determine the time since death or post-mortem interval (PMI). Entomological evidence can provide valuable information about the prediction of the post-mortem interval and where the death occurred.

Forensic entomology, like many other fields in forensic sciences, has been developing using new technologies. Cuticular hydrocarbon (CHC) analysis has become a useful tool for identifying and ageing forensically important blowfly species. Variation in hydrocarbon profiles is significant for climatic adaptation, protection against dehydration and desiccation. The effect of other variables, such as environmental climate and geographic region, and how this may change the CHC structure is not known. In the literature, there are some studies showing differences in the hydrocarbon structure of beetles, fruit flies and house flies when reared at different temperatures. Although there are many studies on the relationship between temperature effect and development time of blowfly species using classical entomology methods, no studies have been conducted using cuticular hydrocarbon analysis. In this regard, this study has been a first in the field of forensic entomology.

In this study, L. sericata collected from the wild were used for oviposition. Once eggs were laid on the oviposition medium, the Petri dish containing the meat was transferred to incubators at 14 ºC, 25 ºC and 34ºC. The cuticular hydrocarbons were chemically extracted and analysed for post-feeding larvae. The effect of temperature changes on the cuticular structure was investigated by using Gas Chromatography-Mass Spectrometry.