Luring houseflies (Musca domestica Diptera: Muscidae) to traps: Do cuticular hydrocarbons and visual cues increase catch?

Abstract

Houseflies (Musca domestica L.) are a major pest species of livestock units and landfill sites used for the disposal of domestic waste. Of the many methods used to limit housefly populations, the most common are chemical control and lure-and-kill trap systems. Insecticide resistance has seen increased emphasis on lure-and-kill, but the success of this method relies on effective attraction of houseflies using olfactory or visual stimuli. Here we examine the efficacy of olfactory (cuticular hydrocarbons) or visual (colours and groups of flies) attractants in a poultry unit. Despite simulating the cuticular hydrocarbon profiles of male and female houseflies, we found no significant increase in the number of individuals lured to traps, or any sex-specific responses. Similarly the use of target colours selected to match the three peaks in housefly visual spectral sensitivity yielded no improvement in catch rate. We also demonstrate that male and female flies have significantly different spectral reflectance (males are brighter between 320-470nm; females are brighter between 470-670nm). An experiment incorporating groups of recently killed flies from which cuticular hydrocarbons were either removed by solvent or left in-tact also failed to show any evidence of olfactory or visual attraction for houseflies of either sex. Thus variations on the most commonly applied methods of luring houseflies to traps in commercial livestock units failed to significantly increase capture rates. Our results support commonly observed inconsistencies associated with using olfactory or visual stimuli in lure-and-kill systems, possibly because field conditions lessen the attractant properties observed in laboratory experiments.