Responses of Ips pini ( Say ) ,

J. Entomol. Sci. 38(4): 602-611 (October 2003) Abstract We conducted seven experiments in stands of mature lodgepole pine in southern B r i t i s h C o l u m b i a t o e l u c i d a t e t h e r o l e o f h o s t volatiles i n t h e s e m i o c h e m i c a l e c o l o g y o f t h e p i n e 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 Lasconofus complex LeConte (Colydiidae), Thanasimus undafulus (Say) (Cleridae) and a Corticeus sp. (Tenebrionidae) were increased by 3-carene. In contrast, attraction of the bark beetle Pityogenes knecbfeli Swaine (Scolytidae) to ipsdienol was interrupted by 3-carene and a-pinene. Attraction of L. complex to ipsdienol was increased by r-terpinene, a compound attractive to the mountain pine beetle, Dendroctonus ponderosae Hopkins (Scolytidae). Terpinolene interrupted the attraction of 1. pini t o i p s d i e n o l .