Effect of Diazepam and Ethanol on External Larval Morphology of Chrysomya megacephala (Diptera: Calliphoridae)

Abstract

Chrysomya megacephala (Diptera: Calliphoridae) is a medically and forensically important blow fly, where larvae of C. megacephala are the most commonly studied insects (in relation to forensic science) that are associated with cadavers at crime scenes, especially the 3rd instar stage. Larvae of C. megacephala had been reared since hatching on freshly excised livers from rabbits (Oryctolagus cuniculus) that had been treated with three different doses each of diazepam, ethanol, or diazepam mixed with ethanol, to compare with the control group, fed with rabbit livers treated with only sterile saline. The external morphological changes, respiratiory slits with bleb formation of the posterior spiracle and swallen anal pads, in the treated C. megacephala larvae could be clearly seen from the Scanning Electron Microscopy (SEM). Thus, diazepam and ethanol cause distinctive external morphological deformation in C. megacephala larvae which could identify the trace of both substances in late stage cadavers.