Identification and Behavioral Evaluation of Ketone Attractants for the Stable Fly, Stomoxys calcitrans

The stable fly, Stomoxys calcitrans L., is one of the most damaging blood-feeding pests of livestock. Stable flies use odors associated with vertebrate hosts and their environments to locate blood meal and suitable oviposition and larval-development sites. Previous studies have identified behaviorally active gases, phenolic compounds, short-chain fatty acids, alcohols, and sulfur-containing compounds from cattle-associated odor sources, but ketones have received limited behavioral investigation. We first evaluated stable-fly attraction to host- and resource-associated substrates, including chicken manure, wet blood meal and sheep blood and characterized volatile compounds from attractive materials using SPME-GC-MS. We then tested ketones detected in the headspace of these substrates or reported in published studies. Three ketones, 1-octen-3-one, 3-octanone, and 6-methyl-5-hepten-2-one, significantly attracted adult stable flies. Following blend evaluation, 3-octanone and 1-octen-3-one were selected as the two-component K-lure blend which was significantly more attractive than the control in choice assays. Combining K-lure with the previously reported phenol-m-cresol blend elicited the highest response among the treatments tested. In a subsequent sticky-card trapping assay, traps baited with K-lure captured significantly more stable flies than the control traps. These results identify ketones as stable fly attractants and support further evaluation of K-lure in trap-based monitoring and management.