Wind-Tunnel Assays to Determine the Effect of Minor Pheromone Components on the Responses of Male Spruce Budworm

Ontario

1990

20 S.

1 Abb., 9 Tab., 23 Lit. Ang.

Serie

8751S

400091090

Bioassays of the sexual behavior of male spruce budworm (Choristoneura fumiferana (Clem.)) were carried out in a wind-tunnel in an attempt to identify minor pheromone components that might improve male responses to the 95:5 blend of the major pheromone components, the unsaturated aldehydes E- und Z-11-tetradecenal. Filter paper and rubber septa were used to dispense the pheromone. The septa were placed on cones of filter paper, which permitted the assay of courtship and copulatory attempts in addition to activation and in-flight responses. Addition of E-11-tetradecenyl acetate, which is present in the female-emitted pheromone at less than 1% of the concentration of the aldehydes, reduced all levels of response at concentration of 10% or greater. Addition of the saturated aldehyde tetradecanal, which is present in the female-emitted pheromone at a concentration of 1-2% of that of the unsaturated aldehydes, had no significant effect on responses, either alone or in combination with the acetate. Addition of hexadecanal had a slightly inhibitory affect on male behavior, but addition of E- or Z-11-hexadecenal had no effect. None of the blends at any of the ratios or concentrations tested evoked responses as high as those evoked by calling, virgin female moths. It is therefore hypothesized that additional unidentified compounds are present in the natural pheromone.