Differential bioactivity of conophthorin on four species of North Americanbark beetles (Coleoptera : Scolytidae)

The angiosperm bark volatile, conophthorin, was tested at release rates of 3.0 and 0.3 mg/24 h against the Douglas-fir beetle, Dendroctonus pseudotsug ae Hopkins, the spruce beetle, Dendroctonus rufipennis (Kirby), the pine en graver, Ips pini (Say), and the western balsam bark beetle, Dryocoetes conf usus Swaine (all Coleoptera: Scolytidae). The responses of D. pseudotsugae. I. pini, and (in one of two experiments) female D. confusus to attractant- baited traps were disrupted by conophthorin in a dose-dependent manner. Den droctonus rufipennis was not disrupted by conophthorin. Our results extend the repellent bioactivity of conophthorin to Ips DeGeer spp. and confirm ea rlier experiments with D. pseudotsugae. Conophthorin may have some utility in protecting susceptible timber from bark beetle attack.