Does verbenone reduce mountain pine beetle attacks in susceptible stands of pondersoa pine?

Verbenone capsules were stapled to trees in mountain pine beetle infested stands of ponderosa pine at densities of 10, 20, 40, and 68 capsules per acre.None of the treatments were effective in reducing the number of attacked trees.The effectiveness of the treatments may have been compromised when above-average temperatures followed early placement of the capsules, which may have degraded the verbenone before peak beetle emergence.