P.J. Silk and E.G. Kettela
SERG Project # 2001/04 (2002)
The jack pine budworm is one of the most serious insect defoliators of jack pine in Canada. Local populations of jack pine budworm characteristically exhibit periodic population outbreaks lasting two or more years, causing top kill, reduced growth, and tree mortality. The rapid onset of JPBW population outbreaks and the subsequent economic damage makes it essential to develop a reliable and practical method for surveying and monitoring populations. We propose the development of a pheromone-based monitoring system that will fulfill this requirement. The work will involve the development of a lure that matches the natural female sex pheromone and the selection of a suitable trap. A pheromone-based monitoring system to detect changes in insect populations can then be implemented when a more potent lure, effective at low densities, is developed..
The specific objectives of year 2 were to elucidate and synthesize the sex pheromone blend equal to an identified female-released blend, develop and test a consistent pheromone/kairomone bait, and elucidate the JPBW/host/pheromone relationships.
Field tests were carried out this year in randomized complete blocks in Ontario, Saskatchewan, and Manitoba to test the effects of the host volatiles α-pinene, β-pinene, terpinolene, 3-carene, and (-)bornyl acetate on pheromone trap capture.
Treatments of pheromone and pheromone/terpene blends caught significantly more males (P<0.01) than terpenes alone or blank lures. Terpene treatments alone captured very few male JPBW. Treatments of pheromone and pheromone/terpene blends were not significantly different (P>0.05) in any of the trap tests in all three provinces. Pheromone-baited traps in Ontario were as good, if not better, in capturing males than traps baited with virgin females. Traps baited with pheromone only caught significantly more males (P<0.05) on jack pine than on white spruce. From this we conclude that host kairomones with pheromone appear not to influence male trap capture rates under these conditions, and the capture of significantly more male JPBW on jack pine as opposed to white spruce may simply reflect local population densities on the two host species.