Blow fly reproductive decisions impact on offspring development in the presence of anthropogenic and environmental stresses

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Understanding the complexity and dynamics of interacting mechanisms remains one of the critical stumbling blocks in predictive applications of animal physiology, behaviour and ecology. This becomes even more critical when the predictive application in question involves estimates of the time of death of unattended human deaths using insect evidence. Insect evidence includes all developmental stages of insects that may be present or associated debris from these developmental stages, as well as any insect behaviour such as insect feeding and timing of adult arrival to the body, timing and location of egg laying on the body as these provide evidentiary value regarding the time frame or conditions of the body prior to discovery. My research focuses on insect reproductive and foraging decisions, and the outcomes of those decisions on the physiology and development of offspring under different abiotic and biotic stresses within natural and managed agroecosystems. I propose to evaluate how anthropogenic and biological mechanisms interact to change blow fly (Diptera: Calliphoridae) reproductive decisions and outcomes for offspring in dead animal based resource systems. Life history traits of blow flies, such as location and timing of egg laying and development of the resulting offspring, are used to provide these estimates of time of death. Despite the direct applicability of these biological metrics to issues of human importance, there are numerous untested assumptions in the literature that tend to be generalized across the family as a whole, such as the specific location that eggs are laid, timing of egg laying, numbers of eggs laid, and lower temperature thresholds for development. Of the 36 species in North America that utilize carrion, or dead animals, basic developmental data exists for less than 1/4 of these species. Even with the few better studied species, there is still debate as to lower temperature thresholds for development, timing of oviposition and limited information regarding other abiotic influences such as humidity or the effect of species interactions on these life history traits. Specifically, my research will measure timing and site selection of egg laying, number of eggs laid, survival, size and development of offspring of different species of blow flies at a range of temperatures, humidities and on different types of animal tissues. These life history traits will be measured for individual blow fly species on their own, as well as in combination with other blow fly species to measure the effect of species combinations on the expression of these traits. Finally, I will measure the distribution of different types of animal tissue sources (i.e. garbage, road kill) and this effect on blow fly species diversity and distribution. Together, this research will provide vital understanding of specific blow fly species life history traits which have direct applicability as insect evidence.