Bark beetle conversion of a plant compound to a sex-specific inhibitor of pheromone attraction.

Both sexes of the bark beetle Dendroctonus brevicomis convert the (+) and (-) enantiomers of the tree terpene alpha-pinene to the corresponding enantiomers of trans-verbenol at about equal rates. (-)-trans-Verbenol inhibited the response of females, but not of males, to a mixture of attractive pheromone components. Since the female initiates the attack on a pine tree, (-)-trans-verbenol may play a role in reducing intraspecific competition for breeding areas.