1st Place: Sexually dimorphic flicker fusion and wing flash frequencies in stable flies and horn flies: A potential basis for augmenting light traps

A fly’s wingbeat frequency may differ with its species, sex, and age. With each cycle, beating fly wings reflect flashes of incident sunlight and generate an acoustic tone matching the wingbeat frequency. These acoustic and visual wingbeat characteristics may both serve as signals which mediate mate location and recognition. Mate-seeking stable fly, Stomoxys calcitrans, males reportedly perch on prominent resting sites from which they take off to pursue and mount passing females. We aimed to determine whether stable flies can sense, and behaviourally respond to, light flashes characteristic of prospective mates. We further studied whether acoustic and visual signals bimodally mediate mate recognition in stable flies, as they do in yellow fever mosquitoes, Aedes aegypti. Our objectives were to (i) determine the flicker fusion frequency (FFF) of the flies’ compound eyes in electroretinogram recordings, (ii) ascertain the flies’ wing flash frequencies through high-speed video recordings, (iii) bioassay whether male flies behaviourally respond to flashing light stimuli, and (iv) study the combined effect of experimentally produced light flash and sound frequencies on attraction of males. Both male and female flies have high and sexually dimorphic FFFs ( >250 Hz) and differ in their wing flash frequencies. Additional behavioral studies were ongoing at the time the abstract submission was due. As stable flies are pests of major veterinary concern, effective stimulants for mate-seeking flies may be used to improve current monitoring tools and auto-sterilizing devices.