Development of an improved attractive lure for the pine shoot beetle, Tomicus piniperda (Coleoptera : Scolytidae)

1 The pine shoot beetle, Tomicus piniperda (L.) (Coleoptera: Scolytidae), is an exotic pest of pine, Pinus spp., and was first discovered in North America in 1992. 2 Although primary attraction to host volatiles has been clearly demonstrated for T. piniperda, the existence and role of secondary attraction to insect-produced pheromones have been widely debated. 3 Currently, commercial lures for T. piniperda include only the host volatiles alpha-pinene in North America and a-pinene, terpinolene and (+)-3-carene in Europe. Several potential pheromone candidates have been identified for T. piniperda. 4 We tested various combinations of host volatiles and pheromone candidates in Michigan, U.S.A., and Ontario, Canada, to determine an optimal blend. 5 Attraction of T. piniperda was significantly increased when trans-verbenol (95% pure, 3.2% cis-verbenol content) was added with or without myrtenol to alpha-pinene or to blends of alpha-pinene and other kairomones and pheromone candidates. 6 Our results, together with other research demonstrating that trans-verbenol is produced by T. piniperda, support the designation of trans-verbenol as a pheromone for T. piniperda. A simple operational lure consisting of a-pinene and trans-verbenol is recommended for optimal attraction of T. piniperda.