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Investigating Upper Thermal Limits of Forensically Important Blow Flies to Improve Testimony in Forensic Entomology

NCJ Number
300811
Date Published
2021
Length
39 pages
Author(s)
Aaron M. Tarone; Travis W. Rusch; Jeffery K. Tomberlin
Agencies
NIJ-Sponsored
Grant Number(s)
2016-DN-BX-0204
Annotation

Since few studies have quantified the effects of temperature on adult blow fly development - such as oviposition, locomotion, and survival - this study examined the thermal biology of two blow fly species, Cochliomyia macellaria Fabricus (Dipteria: Calliphoridae) and Chrysomya rufifacies Macquart (Dipteria: Calliphoridae), as both larvae and adults.

Abstract

Such information could provide evidence that a body has been transported after death, as well as an alternative explanation as to why some dead bodies are found uncolonized by blow flies. The study also investigated the effects of exposing both immature and adult blow flies to suboptimal temperatures to simulate different ecologically relevant scenarios. This study provides information on how suboptimal environmental conditions, such as heat waves or short cold periods, influence adult colonization and larval development. The study then quantified the thermal preferences of both adult and immature (larval) blow flies. The overall results of this study suggest that temperature has major implications for various aspects of blow fly behavior and development. The data from this study aid forensic investigations in at least two ways. First, if the thermal limits of blowflies are known, investigators may be able to explain why some cases lack blow fly colonization. Second, in cases where a body is colonized by larvae in suboptimal temperatures, the presence of blow flies provides evidence that the body was moved after death. The results indicate that oviposition critical temperatures are more limiting than adult thermal knockdown and survival temperatures. Thus, even though adult blow flies may be active in a region, they may opt to not colonize a body if the temperatures fall outside their oviposition thermal limits. 29 figures, 1 table, 19 references, and a listing of scholarly products of the project

Date Created: May 6, 2021