SEMIOCHEMICAL-BASED COMMUNICATION IN INTERSPECIFIC INTERACTIONS BETWEEN IPS PINI (SAY) AND PITYOGENES KNECHTELI (SWAINE) (COLEOPTERA: SCOLYTIDAE) IN LODGEPOLE PINE

Abstract

AbstractThe pine engraver, Ips pini Say, and Pityogenes knechteli Swaine often co-exist in lodgepole pine, Pinus contoita var. latifolia Engelmann. We tested the hypotheses that P. knechteli produces an attractive pheromone and that the attraction of P. knechteli and I. pint to conspecifics is inhibited by the presence of the other species. Pityogenes knechteli males and females were attracted to bolts infested with conspecific males and to bolts infested with I. pini males; however, there was no significant cross-attraction of I. pini males or females to bolts infested with P. knechteli males. Attraction of P. knechteli and I. pint males and females to bolts infested with conspecific males was not inhibited in the presence of bolts infested with males of the other bark beetle species. Pityogenes knechteli has no potential for competitive displacement of I. pini but may enhance the adverse effect of I. pini on the mountain pine beetle, Dendroctonus ponderosae Hopkins.