Responses of Ips pini (Say), Pityogenes knechteli Swaine and Associated Beetles (Coleoptera) to Host Monoterpenes in Stands of Lodgepole Pine

We conducted seven experiments in stands of mature lodgepole pine in southern British Columbia to elucidate the role of host volatiles in the semiochemical ecology of the pine engraver, Ips pini (Say) (Coleoptera: Scolytidae), with particular reference to the behavioral responses of predators and competing species of bark beetles. Our results demonstrated that the attraction of Ips pini and the bark beetle predators Lasconotus complex LeConte (Colydiidae), Thanasimus undatulus (Say) (Cleridae) and a Corticeus sp. (Tenebrionidae) were increased by 3-carene. In contrast, attraction of the bark beetle Pityogenes knechteli Swaine (Scolytidae) to ipsdienol was interrupted by 3-carene and α-pinene. Attraction of L. complex to ipsdienol was increased by γ-terpinene, a compound attractive to the mountain pine beetle, Dendroctonus ponderosae Hopkins (Scolytidae). Terpinolene interrupted the attraction of I. pini to ipsdienol.