Effects of cocaine and heroin, and their combination, on the development rate of Calliphora vomitoria (Diptera: Calliphoridae). Issue 4 (July 2022)

• Record Type: Journal Article
• Authors: Wood, T.; Pyper, K.; Casali, F.
• Is Part Of: Science & justice. Volume 62:Issue 4(2022)
• Page Start: 471
• Page End: 475
• Publication Date: 2022-07
• Subjects: Calliphoridae -- Entomotoxicology -- Heroin -- Cocaine -- Drug combination -- Insect growth rates; Forensic sciences -- Periodicals; Criminal investigation -- Periodicals; Forensic Medicine -- Periodicals; Jurisprudence -- Periodicals; Criminalistique -- Périodiques; Enquêtes criminelles -- Périodiques; Criminal investigation; Forensic sciences; Electronic journals; Periodicals; 363.2505
• DOI: 10.1016/j.scijus.2022.07.001
• Languages: English
• ISSNs: 1355-0306

Abstract

Highlights: Cocaine-fed larvae developed less in length and weight than the control. Heroin-fed larvae had a more sluctuating development than the control. Combination-fed larvae seemed to favour the effects of cocaine rather than heroin. Cocaine and combination-fed larvae increased second and third instar stages, but shorten pupation and accelerate eclosion. Heroin increases second instar stage and pupation. Abstract: Insects present on or near decomposing bodies are collected by forensic entomologists and used to estimate the post-mortem interval. Drugs metabolized by a person before death may affect the rate of development of insects feeding on the corpse. This study aimed to determine the effects of cocaine and heroin main metabolites on the development rate of the Calliphora vomitoria (Diptera: Calliphoridae) and their implications on minimum post-mortem interval determination. Groups of 250 eggs each were placed into four separate pots of 150 g of minced pork meat being either un-spiked, or spiked with benzoylecgonine, morphine, or a combination of both. Larval length (mm) and weight (mg) measurements were taken twice daily and the rate of development of the insects' life cycle was monitored until eclosion. Results show that cocaine-fed larvae developed less in length and weight than the control group. Heroin-fed larvae showed a more fluctuating pattern, being smaller and lighter than the control group for most of their larval cycle, but overtaking them in both parameters towards pupation. Combination-fed larvae seemed to favour the effects of cocaine. The three conditions also had a significant impact on the length of the insects' life cycle. Cocaine and drug combination treatments increased the length of the second and third instar stages, but led to the shortening of pupation and accelerated eclosion. Conversely, heroin treatment led to lengthier pupation. Interestingly, the effects of the drug combination seemed to mirror more precisely those of cocaine. These findings indicate that both cocaine and heroin, singularly and in combination, have sizable effects on blowflies' development rates, potentially biasing post-mortem interval estimations.