EVIDENCE FOR AN AIRBORNE SEX-PHEROMONE IN THE COLORADO POTATO BEETLE,LEPTINOTARSA-DECEMLINEATA

Trials using four different sex combinations of Colorado potato beetle , Leptinotarsa decemlineata Say, demonstrated that male beetles move u pwind towards females, whereas no attraction was seen between any of t he other combinations. Attraction was not found to increase significan tly after the female reached 10 days old. Visual stimuli appeal to be unimportant from a distance of 50 cm. Orientation behaviour by the mal e beetle was observed as it walked upwind towards the female; no ident ifiable calling behaviour by the female was observed. The data indicat e a sex pheromone is being produced by the female and is used by the m ale for mate location from a distance.