Focus stacking technique in identification of forensically important Chrysomya species (Diptera: Calliphoridae)

Abstract

Entomological evidence showed great role in death investigations during the last decades. This depends mainly on identification of insect samples by expert taxonomists who are not available among forensic investigator teams in Egypt which represents one of the obstacles that prevent the use of entomological evidence.This study aimed to provide easily used key for identification of Egyptian Chrysomya species using focus stacking technique that can be applied in forensic investigation. Materials and methodsCollection of flies was done using fly traps that were hung in urban districts of Cairo during June–September 2014. Continuous shooting photography of the collected flies was done using a Nikon Stereomicroscopy and camera of smart phone (Galaxy S5), stacking of partially focused images was done by Zerene Stacker software. Chrysomya species were identified and separated from other metallic calyptrate dipteral based on its characteristic morphological features. ResultsSeventy six Chrysomya specimens were collected; Chrysomya albiceps was the most abundant (39) with 16 male and 23 females, followed by Chrysomya megacephala (34) with 13 male and 21 females. Three Chrysomya marginalis were recovered; one male and two females. ConclusionThis study presents simple method for photographing of insect samples that can be used by untrained personals for further identification by expert taxonomists. RecommendationsFurther studies on the blowfly species that occur in Egypt and documentation of their key for identification are recommended to facilitate the diverse applications of these important insects in forensic investigations.