THE ROLE OF 1-OCTEN-3-OL AS A HOST-ODOR ATTRACTANT FOR THE BITING MIDGE, CULICOIDES IMPUNCTATUS GOETGHEBUER, AND INTERACTIONS OF 1-OCTEN-3-OL WITH A VOLATILE PHEROMONE PRODUCED BY PAROUS FEMALE MIDGES

1-octen-3-ol, a component of the body odour of ruminants, is demonstra ted to be an attractant for host-seeking, parous female Culicoides imp unctatus Goetghebuer (Diptera, Ceratopogonidae). This compound was ele ctrophysiologically and behaviourally active and, in the field, releas ed at 0.11 +/- 0.01 mg/day, increased female C. impunctatus catches ov er a seven-day period compared with control catches. When 1-octen-3-ol was combined either with live female midges or an extract of female m idges in an electroantennogram assay, additive effects were recorded. Behaviourally, the same combination resulted in both enhanced attracti on and repellency, depending on concentration. Attraction was recorded mainly when sub-threshold concentrations of the separate components w ere combined. The potential of such a combination as an effective fiel d bait is discussed.