Identification of Oviposition Attractants of the Secondary Screwworm, Cochliomyia macellaria (F.) Released from Rotten Chicken Liver

Abstract

The secondary screwworm, Cochliomyia macellaria (F.), is an important blowfly species affecting both livestock and humans. It can transmit pathogenic disease agents mechanically and is an agent of facultative myiasis, which leads to economic losses. The adult flies are attracted to decomposing carcasses, carrion, or rotten meat in order to deposit their eggs, and the hatched larvae develop on these decaying organic materials. This research was aimed to identify volatiles emitted from rotten chicken livers that were reported previously to attract gravid females. In laboratory oviposition assays, gravid females laid significantly more eggs on rotten livers than on fresh livers, and rotten chicken liver was more attractive than rotten beef liver. Volatiles from the two livers were collected using solid phase microextraction. Significantly different volatile profiles were detected from the rotten livers of beef and chicken. Electroantennography (EAG) was performed to determine antennal responses to chemicals released from the most attractive chicken liver that are candidate oviposition attractants. Seven compounds from rotten chicken liver elicited significant EAG responses from antennae of gravid females. Oviposition assays showed that the 7-component blend stimulated gravid females to lay significantly more eggs than the other combinations tested. This 7-component blend may have potential for use in monitoring and sampling populations of secondary screwworm and their associated disease epidemiology.