SEX-PHEROMONE MEDIATED BEHAVIOR OF THE NAVEL ORANGEWORM, AMYELOIS-TRANSITELLA (LEPIDOPTERA, PYRALIDAE)

The female navel orangeworm, Amyelois transitella (Walker), produces a sex pheromone that elicits both sexual excitation and upwind flight of males in laboratory bioassays. Quantitative bioassays were developed that employed either orientation (upwind movement) or activation (locomotion, wing-fluttering, clasper extension) as response criteria. Pheromone was released by females only during the last 1/3 of a 10-h scotophase, a time that coincided with maximal male pheromone responsiveness and mating. There were no significant differences between 1-, 2-, 3-, or 4-day-old unmated females in either the percentage of females calling or in the quantity of pheromone present in the superficial rinses of of excised abdominal tips during the 8th-10th h of the scotophase. Similarly, no significant differences were observed in pheromone responsiveness in 2- to 3-, or 4-day-old unmated males. Mating resulted in >90% reduction in female calling and at least a 10-fold decrease in the quantity of extractable pheromone. The activation and orientation responses of laboratory males did not differ significantly when pheromone extracts were prepared from either laboratory-reared or feral (collected as last-instar larvae) females. © 1979 Entomological Society of America.