A sex attractant of the cabbage webworm, Hellula undalis Fabricius (Lepidoptera: Pyralidae)

Abstract

Recently, crop damages by the cabbage webworm, Hellula undalis Fabricius (Lepidoptera: Pyralidae), has been frequently observed in Japan, and the development of a species-specific trap for monitoring of the field population is required. Unfortunately, the attraction activity of the known sex pheromone of this species, (E,E)-11,13-hexadecadienal, is too weak to be effective in a lure for this trap. Thus, we began field screening tests to find compounds that could enhance the attraction activity of (E,E)-11,13-hexadecadienal. In the tests, we found that a mixture of 5 μg of (E,E)-11,13-hexadecadienal and 15-500 ng of (Z)-11-hexadecenal showed the same attraction activity as virgin females. The existence of this compound was not confirmed in the extract of virgin females.