Mountain pine beetle, Dendroctonusponderosae Hopkins, is the primary pest affecting lodgepole pine, Pinuscontorta var. latifolia Engelm., ecosystems in western North America. In 1988, aerial treatments of the antiaggregation pheromone, verbenone, were applied to lodgepole pine stands infested with mountain pine beetle in northwestern Montana. The pheromone was formulated by PHERO TECH Inc. in controlled-release, cylindrical 5 × 5 mm plastic beads and applied without benefit of a sticker at the rate of 54 g verbenone per hectare. There were significantly fewer successfully attacked trees on the treated plots, as evidenced by (i) a fourfold greater incidence of current-year attacked trees per hectare in the untreated check plots and (ii) the significantly lower (α = 0.05) ratio of 1988:1987 attacked trees in the treated plots. Further, the number of trees per hectare resisting attacks (as reflected by number of trees pitching out bark beetles) was higher (α = 0.05) in the treated plots. More pitch outs occurred in treated plots presumably because avoidance of verbenone by beetles reduced the number of beetles below that needed to overcome the natural resistance of attacked trees.

Abstract The attack density of the spruce beetle, Dendroctonus rufipennis (Kirby), was reduced to 10-25% of that on untreated felled Engelmann spruce (Picea engelmannii) trees, when the trees were treated with 9-15 bubble cap release devices, each releasing the aggregation inhibitor MCH at 1-3 mg/24 h at 20°C. In the first experiment, deterioration of many release devices reduced the suppression effect. In the second experiment, MCH reduced attacks by 85%, and total brood production by 79-88%. The attacks on the MCH treated trees occurred late, as evidenced by the early stage of development of galleries and brood on these trees. Semiochemical-baited traps at untreated, or MCH-treated, felled trees caught few beetles, and had no effect on the attack density. The results show that manually applied MCH can be used operationally to reduce attacks by the spruce beetle on small groups of wind thrown trees. Mass trapping of spruce beetles is not feasible with currently known semiochemicals. West. J. Appl. For. 4(2):49-52, April 1989.

AbstractThe attack density of the Douglas‐fir beetle, Dendroctonus pseudotsugae, was reduced to 3–7% of that on untreated Douglas‐fir trees, Pseudotsuga menziesii, when the trees were treated with bubble cap release devices releasing MCH at 3 mg/24 h stapled to the tree trunk at 3 m intervals. Density dependence of brood development suggests that brood emergence was not as dramatically affected by the MCH. Lindgren funnel traps baited with aggregation pheromones did not significantly affect attack density.ZusammenfassungZur Wirkung von MCH und Lindgren‐Pheromonfallen auf den Befall gefällter Douglas‐Tannen durch Dendroctonus pseudotsugaeDie Befallsdichte von D. pseudotsugae bei gefällten Douglas‐Tannen (Pseudotsuga menziesii) wurde auf 3–7% der Dichte‐Werte an unbehandelten Stämmen reduziert, wenn die gefällten Stämme mit MCH abgebenden (3 mg/24 h) Gummibechern in 3‐m‐Abständen bestückt wurden. Die Borkenkäferbrut wurde durch die MCH‐Freisetzung nicht wesentlich beeinflußt. Lindgren‐Trichterfallen, die mit Aggregations‐Pheromonen beködert waren, zeigten keinen signifikanten Einfluß auf die Befallsdichte der Käfer.

The mountain pine beetle, Dendroctonus ponderosae Hopkins, is a member of a group of beetles known as bark beetles: Except when adults emerge and attack new trees, the mountain pine beetle completes its life cycle under the bark. The beetle attacks and kills lodgepole, ponderosa, sugar, and western white pines. Outbreaks frequently develop in lodgepole pine stands that contain well-distributed, large-diameter trees or in dense stands of pole-sized ponderosa pine. When out-breaks are extensive, millions of trees may be killed each year. Periodic losses of high-value, mature sugar and western white pines are less wide-spread but also serious.