Response of Culicoides spp. (Diptera: Ceratopogonidae) to light-emitting diodes

Light traps with incandescent globes are used in a national monitoring program to detect the presence of Culicoides spp. responsible for the transmission of viruses to livestock and native animals. Recent events have suggested that the efficiency of these traps should be reconsidered and possibly improved. Subsequently, the response of eight species of Culicoides to light-emitting diodes (LEDs) was determined at two locations in New South Wales. Culicoides austropalpalis Lee & Reye, C. bunrooiensis Lee & Reye and C. marksi Lee & Reye were attracted to blue light. Responses to blue and green light could not be separated for C. bundyensis Lee & Reye, C. dycei Lee & Reye, C. nattiensis Lee & Reye and C. victoriae Macfie. Culicoides brevitarsis Kieffer was significantly attracted to green light. This species is the major vector of Akabane and bluetongue viruses in Australia. These responses were all significantly greater than the responses to the incandescent lights currently used in the light traps. The response to red light was less than the response to incandescent light for all species. Catches of C. brevitarsis were also related to the intensity of the green LEDs. These were more effective than the currently used incandescent globes at intensities between 46% and 142% of the incandescent intensity.