Response of Lucilia sericata (Diptera: Calliphoridae) to Screwworm Oviposition Attractant

Authors: Chaudhury, Muhammad; Zhu, Junwei - Jerry; Skoda, Steven

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2015
Publication Date: 7/1/2015
Citation: Chaudhury, M.F., Zhu, J.J., Skoda, S.R. 2015. Response of Lucilia sericata (Diptera: Calliphoridae) to Screwworm Oviposition Attractant. Journal of Medical Entomology. 52(4):527-31.

Interpretive Summary: Sheep blow flies cause skin lesions and wounds in sheep in various parts of the world including the Americas. Sheep blow fly females, attracted to sheep by various smells emanating from the sheep's body, deposit eggs on suitable surfaces of the sheep's body causing an infliction called myiasis (maggots living on, parasitizing, the living flesh of other animals). Earlier workers attempted to reduce fly populations in the field with some success using traps baited with various chemicals and other materials to attract flies to the traps. We investigated the sheep blow fly female's response to synthetic attractants that cause egg-laying in screwworms (a closely related species). Results of the laboratory study demonstrated that the gravid (ready to deposit eggs) females were attracted to the substrates treated with the synthetic screwworm attractant composed of five specific chemical compounds. Tests with various combinations of these compounds suggested that the two sulfur compounds and an organic chemical, indole, are the most important compounds to cause attraction and stimulate egg-laying. These findings suggest that baits based on these chemical compounds may be useful in the field to trap gravid sheep blow flies for sampling and suppression.

Technical Abstract: The sheep blow fly, Lucilia sericata Meigen (Diptera: Calliphoridae), causes sheep myiasis in various parts of the world. The females are attracted to sheep, following various olfactory cues emanating from the sheep's body, and oviposit on suitable substrates on sheep ultimately causing myiasis. Earlier workers attempted to reduce fly population in the field with some success using traps baited with various attractants. This research was conducted to investigate if L. sericata will respond to recently-developed synthetic attractant that results in oviposition in screwworms. Results of the laboratory bioassays demonstrated that gravid female L. sericata were attracted in significant numbers to the substrates treated with the synthetic screwworm attractant composed of five compounds – dimethyl disulfide, dimethyl trisulfide, phenol, p-cresol, and indole. Tests with various combinations of these compounds suggest that the sulfur compounds and indole are the most important compounds to elicit attraction and stimulate oviposition; the phenol and p-cresol may have a minor role in evoking attraction. These findings suggest that semiochemical baits based on these compounds may be useful in the field to trap gravid L. sericata.