Detection of volatile pheromone candidates from the white-spotted longicorn beetle, Anoplophora malasiaca (Coleoptera: Cerambycidae)

Anoplophora malasiaca (Thomson) (Coleoptera: Cerambycidae) is a serious pest that affects various crop trees and landscapes in Japan. We collected and analyzed volatiles from male and female A. malasiaca. 4-(n-Heptyloxy)butan-1-ol and its aldehyde, pheromone components in A. glabripennis and A. chinensis, were detected in the male volatile extracts and nonanal both in the male and female volatile extracts. Nonanal was absent from the extracts of twigs of the willow host plant. Gas chromatograph-electroantennographic responses showed that nonanal and 4-(n-heptyloxy)butan-1-ol elicited responses from both male and female antennae, but 4-(n-heptyloxy)butanal did not. Volatiles of eight artificially reared males, analyzed every 3 or 4days for 60days from adult emergence showed that they all produced nonanal and 4-(n-heptyloxy)butan-1-ol. The two compounds produced no short-range female attraction but in males, the short-range attraction to nonanal was dose dependent and significant in a higher dose, but did not depend on 4-(n-heptyloxy)butan-1-ol. When wounded willow twigs were added to nonanal and 4-(n-heptyloxy)butan-1-ol, the frequency of male responses was higher than in all other treatments, but the same as wounded willow twigs alone. The wounded host plant willow twigs might thus be enough for male attraction. The identified volatiles from the beetles in the present study might have a weaker function for attraction from the distance compared to their host plant volatiles.