The role of 1-octen-3-ol as a host-odour 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 demonstrated to be an attractant for host-seeking, parous female Culicoides impunctatus Goetghebuer (Diptera, Ceratopogonidae). This compound was electrophysiologically and behaviourally active and, in the field, released at 0.11 +/- 0.01 mg/day, increased female C. impunctatus catches over 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 midges in an electroantennogram assay, additive effects were recorded. Behaviourally, the same combination resulted in both enhanced attraction and repellency, depending on concentration. Attraction was recorded mainly when sub-threshold concentrations of the separate components were combined. The potential of such a combination as an effective field bait is discussed.