Nonconsumptive effects of predatory Chrysomya rufifacies (Diptera: Calliphoridae) larval cues on larval Cochliomyia macellaria (Diptera: Calliphoridae) growth and development

Authors: FLORES, MICAH - Texas A&M University; Crippen, Tawni - Tc; LONGNECKER, MICHAEL - Texas A&M University; TOMBERLIN, JEFFERY - Texas A&M University

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/26/2017
Publication Date: 9/1/2017
Publication URL: https://handle.nal.usda.gov/10113/5832860
Citation: Flores, M., Crippen, T.L., Longnecker, M., Tomberlin, J.K. 2017. Nonconsumptive effects of predatory Chrysomya rufifacies (Diptera: Calliphoridae) larval cues on larval Cochliomyia macellaria (Diptera: Calliphoridae) growth and development. Journal of Medical Entomology. 54(5):1167-1174. https://doi.org/10.1093/jme/tjx104.
DOI: https://doi.org/10.1093/jme/tjx104

Interpretive Summary: Forensic entomologists often rely on development data associated with a given species to estimate when it colonized human or other vertebrate remains. In most instances, these development studies are based on single species reared in isolation in the laboratory. This study examined the impact of unfiltered or filtered (to remove microbes) excretions/secretions (ES) associated with the larvae of the hairy maggot blow fly, a predator, on the development of its prey, the secondary screwworm. Predator ES impacted the development of the prey larvae (third instar). Exposure to unfiltered ES resulted in larvae that were longer and completed formation of the enclosing case of the fly pupa 8 h quicker than those in the control. Exposure to filtered ES resulted in normal sized larvae and dampened the time required for pupa formation by fifty percent. Secondary screwworm larvae treated with filtered or unfiltered hair maggot blow fly ES reached adulthood approximately 5 h faster than those treated with dH2O. In summary, these data have large implications for forensic entomology as multiple species being present on decomposing remains is not uncommon. Understanding the impact of the specific ES produced by multispecies cohorts on overall development could lead to more precise estimates of the time of colonization of decomposing remains.

Technical Abstract: Forensic entomologists often rely on development data associated with a given species to estimate when it colonized human or other vertebrate remains. In most instances, these development studies are based on single species reared in isolation in the laboratory. This study examined the impact of excretion/secretions (ES) associated with third instar Ch. rufifacies, a predator, on the development of its prey, C. macellaria. Not surprisingly, Ch. rufifacies ES did not impact the development of first or second instar C. macellaria, which are typically not preyed upon by Ch. rufifacies. However, development of third instar C. macellaria, which are preyed on by third instar Ch. rufifacies, was impacted. First, larvae were longer than those in the control. Filtering the ES and removing the associated bacteria negated the previous impact observed of the ES on third instar C. macellaria. Second, third instar C. macellaria treated with unfiltered ES completed pupariation 8 h quicker than the control. Filtering the ES dampened effect by fifty percent. And third, third instar C. macellaria treated with filtered or unfiltered Ch. rufifacies ES reached adulthood approximately 5 h faster than those treated with dH2O. In summary, these data have large ramifications for forensic entomology as multiple species being present on decomposing remains is not uncommon. Understanding the impact of associated ES produced by interspecific cohorts on associated development could lead to more precise estimates of the time of colonization of decomposing remains.