Sensory Morphology and Chemical Ecology of the Stable Fly, Stomoxys calcitrans: Host-Seeking and Ovipositional Selection

Stable flies cause stress and discomfort to cattle, and other mammals, including humans and pets. Economic losses from stable flies to the U.S. cattle industry from loss of milk production and cattle weight gain exceed $2 billion annually. Traditional stable fly management employing sanitation and insecticides is costly and often fails to provide acceptable levels of control. A novel method for managing stable flies involves the use of attractants and repellents. This approach could be used to enhance the current level of stable fly control and ultimately be incorporated into a sustainable stable fly management program. Gravid females’ stable flies use chemical cues from host animals and the environment to locate suitable hosts, mates, and oviposition sites. Understanding stable fly olfaction and the electrophysiological responses to host seeking and ovipositional stimuli is essential for exploring stable flies’ behaviors stimulated by odor cues. This study characterized the number, location and types of stable fly sensilla on antennae. Accompanying electroantennogram studies assessed antennal responses to host-associated volatile compounds. The attractiveness / repellency of selected naturally occurring compounds to stable fly feeding and oviposition were investigated under laboratory and field conditions. Four majors’ types of sensilla were documented: basiconic, clavate, coeloconic, and trichoid with three subtypes. Results of electroantennogram studies revealed significant antennal responses to host-associated compound; for example, 1-octen3-ol, phenol, p-cresol, indole, and dimethytrisulfide. Catnip (Nepeta cataria L.) oil and its constituent nepetalactones compounds provided significant repellency of stable flies. Combinations of host derived volatile compounds (phenol and m- or p-cresol) were more attractive to stable flies than a single compound alone. Advisors: Frederick P. Baxendale and Junwei J. Zh