TRANSFER, PERCEPTION, AND ACTIVITY OF MALE PHEROMONE OF ACROLEPIOPSIS-ASSECTELLA WITH SPECIAL REFERENCE TO CONSPECIFIC MALE SEXUAL INHIBITION

In the leek moth, Acrolepiopsis assectella, the male, stimulated by a calling female, produces a sexual pheromone that is active on the fema le. The male-produced pheromone blend contains eight alkanes previousl y isolated from the male hair-pencils. We used EAG techniques to study the effect of the pheromone on females reared on leek or on artificia l diet and on males reared on leek. The optimal stimulation duration a ppeared to be 1.6 sec exposure to the pheromone or components. The con centrations tested on the antenna were of the order of 10(12) molecule s/cm(3). The hair-pencil extract tested was of an estimated concentrat ion of around 10(9) molecules/cm(3). The antennal responses are expres sed relative to responses to a standard, amyl acetate, but also as an absolute value. Generally, females reared on artificial diet and males reared on leek responded better than females reared on leek. Of the a lkanes tested, those present in hair-pencils gave higher responses, wi th hexadecane always giving the strongest response. A possible inhibit ing activity of male leek moth pheromone on the sexual behavior of con specific males was investigated. The behavior of sexually stimulated m ales was observed in the presence of other males, hair-pencil extracts , and different compounds either pure or in a mixture. The experiments established that in this species, male pheromone inhibits wing flutte ring duration of conspecific males. This inhibition was obtained not o nly with fluttering males as a source of pheromone but also with all t he alkanes tested. The inhibition was due to hair-pencil chemicals, pa rticularly if these were perceived by olfaction plus contact. Wing flu ttering increased the inhibitory activity of male-derived alkanes.