Field assessment of honeydew odors for attraction of house flies (Musca domestica)

House flies are considered filth flies since they breed and feed in animal waste, which are commonly produced in animal facilities. They are of major concern in animal agriculture and public health since they can mechanically transmit food-borne pathogens to their surroundings by dispersing from their breeding site and depositing contaminants where they land. Filth flies contaminated with Escherichia coli O157:H7 have been collected in leafy greens crops adjacent to cattle pastures suggesting that flies pose a food safety risk when dispersing into human food crops. Filth flies are not typically associated with leafy green crops, however they were found to be more abundant when honeydew-producing insects were present. House flies have exhibited attraction to multiple honeydew-infested plants in behavioral bioassays. Following positive fly response to honeydew in the bioassay, honeydew volatile odors were collected from the samples using an aeration device. These collected volatiles were used with coupled gas chromatography electroantennogram detection (GC-EAD) and mass spectrometry (GC-MS) to identify any volatile compounds that elicit house fly antenna response. These identified volatiles were used to create different treatment baits and were deployed in traps on a dairy facility to examine their attraction in the field. Examining attractive honeydew volatile odors will bolster efforts to develop effective baits for house fly management.