MATING DISRUPTION OF WESTERN PINE SHOOT BORER (LEPIDOPTERA, OLETHREUTIDAE) IN LODGEPOLE PINE

Pheromone disruption of the mating western pine shoot borer, Eucosma s onomana Kearfott, was tested in young lodgepole pines, Pinus contorta Douglas, in central Oregon. About 12.5 g of pheromone per hectare was applied in Hercon luretape to five 6-ha plots each year for 3 yr. Inci dence of shoot borer larvae in terminal shoots was reduced from 77% in fested in untreated plots to 48% in treated plots. This degree of effi cacy, although statistically significant, was insufficient to result i n measurably increased tree growth. Efficacy was lower than previously demonstrated in ponderosa pine, Pinus ponderosa Douglas ex Laws. Term inals of trees located toward the treated plot centers were less likel y to be infested than those near the edges.