FIELD AND LABORATORY EVIDENCE FOR A VOLATILE PHEROMONE PRODUCED BY PAROUS FEMALES OF THE SCOTTISH BITING MIDGE, CULICOIDES IMPUNCTATUS

Electrophysiological, behavioural and field evidence is presented for a volatile attractant produced by host-seeking, parous female Culicoid es impunctatus Goetghebuer. Attraction of host-seeking females to othe r live parous females or to extracts of parous females was demonstrate d in Y-tube bioassays, as well as in field trials using baited sticky traps. Threshold numbers were 100-200 females, both in the laboratory and field. Antennal receptors to this pheromone were revealed by recor ding electroantennograms (EAGs) in response to odour from live parous females and to the extracts of female midges. The female-produced attr actant did not alter field catches of male C. impunctatus.