Bark beetle olfaction: Pheromone receptor system in Dendroctonus frontalis

Differential adaptation of antennal olfactory acceptors and electroantennogram (EAG) techniques were used to describe the acceptor population for pheromones and host compounds. All acceptors appeared to have some degree of specificity for the pheromone, frontalin. This conclusion was verified by both EAG and single unit recordings. The oxygen containing pheromones occupied a larger percentage of the acceptors than the hydrocarbon host tree terpenes. Pheromones produced by one sex occupied a larger percentage of the pheromone acceptors in the opposite sex. Single unit recordings indicated a chiral acceptor. (-)-Exo-brevicomin stimulation elicited a greater number of impulses in the cells recorded than equal quantities of the (+)-enantiomer. Electrophysiological data correlated well with behavioral rôles attributed the compounds tested.