Development and Validation of a Method for the Detection of α- and β-Endosulfan (Organochlorine Insecticide) in Calliphora vomitoria (Diptera: Calliphoridae)

Abstract

Entomotoxicology studies employ analytical methods and instrumentation to detect chemical substances in carrion insects feeding from the decomposing tissues. The identification of such chemicals may determine the cause of death and may be used for the estimation of the minimum time since death. To date, the main focus of entomotoxicological studies has been the detection of drugs, whereas little information concerns the effects of pesticides on blowflies. Pesticides are generally freely available and more affordable than drugs but they can also be a home hazard and an accessible candidate poison at a crime scene. A QuEChERS extraction method followed by Gas chromatography-mass spectrometry (GC-MS) analysis was developed for the detection of α- and β-endosulfan (organochlorine insecticide and acaricide) in Calliphora vomitoria L. (Diptera: Calliphoridae) and validated. Furthermore, the effects of endosulfan on the morphology, development time and survival of the immature blowflies were investigated. Larvae were reared on liver substrates homogeneously spiked with aliquots of endosulfan corresponding to the concentrations found in body tissues of humans and animals involved in endosulfan poisoning. Results demonstrated that the combination of QuEChERS extraction and GC-MS provide an adequate methods to detect both α- and β-endosulfan in blowfly immatures. Furthermore, the presence of α- and β-endosulfan in the food source 1) prevented C. vomitoria immatures reaching the pupal instar and, therefore, the adult instar at high concentrations, 2) did not affect the developmental time of blowflies at low concentrations 3) affected the size of immatures only at high concentrations, resulting in significantly smaller larvae.

Reduced body length and morphological disorders in Chrysomya albiceps (Diptera: Calliphoridae) larvae reared on aluminum phosphide-treated rabbits

“…Toxins also affect the growth rate of fly larvae developing on the corpses. Many studies have assessed the impact of drugs/pesticides on the morphometry of fly species 25,26 and their development 20,27,28 in terms of forensic entomotoxicology. The vast majority of drugs accelerate the development of larvae, while pesticides tend to delay it.…”

Reduced body length and morphological disorders in Chrysomya albiceps (Wiedemann, 1819) (Diptera: Calliphoridae) larvae reared on aluminum phosphide-treated rabbits

“…Toxins also affect the growth rate of y larvae developing on the corpses. Many studies have assessed the impact of drugs/pesticides on the morphometry of y species 35,36 and their development 31,37,38 in terms of forensic entomotoxicology. The vast majority of drugs accelerate the development of larvae, while pesticides tend to delay it.…”

“…Morphometric studies: The length (mm) of C. albiceps larvae was determined using a Verneer Caliper at various time intervals (12,24,36,48,60,72,84, and 102 hours) A sampling of larvae for quantitative analysis of AlP: Twenty third instar larvae were randomly collected ve days after egg hatching from all carcasses of rabbits in the control and treated groups and then rinsed in phosphate buffer, frozen, and stored at -80°C until toxicological analysis 29 .…”

Recent Advances on Detection of Insecticides Using Optical Sensors

“…Another application was used to treat scabies and lice. It is also used in agriculture for controlling pest on variety of crops [ 302 , 303 ]. In households, it can be used in mothproofing to clothes and carpets [ 304 ].…”