Developmental plasticity of the secondary screwworm, Cochliomyia macellaria Fabricius (Diptera: Calliphoridae), in Texas

Phenotypic plasticity, or the ability of a single genotype to produce multiple phenotypes under alternative stresses, has been documented in genetic and ecological literature and spans across many phyla. Taking this into account, different subpopulations of forensically pertinent insect species should also possess the ability to adapt to changing environments as geographic distribution increases. Thus, plastic responses of a species to alternative stresses may be measured in biological parameters, such as development time. In this research, three geographically distinct populations of the secondary screwworm, Cochliomyia macellaria Fabricius (Diptera Calliphoridae), a common blow fly collected from human remains in the southern U.S.A., were reared in two distinct environments in order to determine differences in development time. It was demonstrated that significant differences in development time exist between conspecific blow fly populations in Texas. This research demonstrates the importance of considering geographic distribution as a source of variability when estimating a time of colonization event.