A preliminary study of the effects of environmental variables on early Diptera carrion colonizers in Algiers, Algeria

Abstract

Necrophagous insects usually colonize cadavers within a short period after death, but can be influenced by weather conditions. Their activity may vary which affects the post-mortem interval (PMI) estimation. In order to study the effect of environmental variables on necrophagous Diptera visiting corpses, two field surveys were conducted in July 2012 and March 2013 at the National Institute for Criminalistics and Criminology (NICC) using rabbit carcasses (Oryctolagus cuniculus L.). The trials were designed to identify the necrophagous Diptera fauna of Algiers, Algeria and examine their variations according to environmental variables. Four hundred and eighteen Diptera adults belonging to five families were captured during this study. Although seasonal variations of the species were observed, their abundance did not significantly vary between the two seasons. In addition to seasonal effects, the ambient temperature, the wind speed, and precipitation affected the number of trapped flies. These conclusions highlight the necessity of considering the environmental factors at a scene to estimate the post-mortem interval accurately. It is hoped that these findings provide basic information regarding the necrophagous Diptera fauna of Algeria.