Dr. Peter Silk, Edward Kettela
Silk Biochemical Services
SERG Project #2001/04
Year of Project: 2003
Report Received: 2004
Jack pine budworm (Choristoneura pinus pinus Freeman) pheromone trapping trials with purified lure components loaded into cleaned red rubber septa were carried out concurrently in Saskatchewan, Manitoba, Michigan, and New Brunswick.
The four pheromone components were obtained from Bedoukian, USA, analysed by GC/MS, and purified prior to use by procedures such as chromatography, silica gel column chromatography, and microdistillation. Several positional isomers and other impurities were identified and removed or reduced in quantity.
Pherotec wing traps were supplied to all partners and used throughout the field trapping. Spare trap bottoms were supplied so that these could be changed as traps became saturated.
In the experiment, six treatments per site were placed out. Additional traps baited with live virgin female jack pine budworm were deployed in Michigan. The blends on the septa consisted of the known blend (Silk et al. 1985), i.e., 100 µg of a 9:1 blend 85/15E/Z11-14:Ac’s and 85/15E/Z11-14:OH’s as received, with and without anti-oxidant (BHT) and a blank (hexane). An additional treatment included all components (no BHT) but excluded the Z11-14:OH component for a total of 6 treatments. All were placed in the field (6 replicates) in predominantly jack pine areas in randomized complete block designs with 20-m trap spacing at head height on pine foliage.
Although statistical analyses have not shown highly significant differences between trap means (very low numbers in New Brunswick), they do show that partial purification of the lure components had an effect and that the synthetic lure out-competes virgin female C. pinus pinus trap capture of males. In Saskatchewan and Manitoba, BHT had little or nor effect on trap capture.
We conclude that purified pheromone components consisting of 100 µg 9:1 of 85/15E/Z11-14:Ac’s and 85/15E/Z11-14:OH’s on red rubber septa provide an improved and more consistent lure that out-competes virgin females as trap baits and appears to be relatively sensitive at lower insect densities. For practical purposes, however, we recommend the use on red rubber septa of the Bedoukian active material because of its availability, provided that the quality of purity is monitored. Use of the Multipher (non-saturating) trap should be explored because of the inherent problems of sticky trap saturation.