Efficacy of 4-allylanisole-based products for protecting individual loblolly pines from Dendroctonus frontalis Zimmermann (Coleoptera: Scolytidae)

We evaluated the effectiveness of 4-allylanisole (4AA) as a protective treatment for loblolly pines threatened by the southern pine beetle, Dendroctonus frontalis Zimmermann. Three products were evaluated in combination with two methods that promoted attack of trees by D. frontalis. One method used attractive semiochemicals and the other decreased host resistance, both of which are important scenarios for implementing protective treatments of individual trees. Each method promoted mass attack of unprotected control trees, thus providing a statistically verifiable challenge to the candidate protectants. In trees with increased susceptibility, mortality ranged from 63% (untreated) to 77% (4AA applied in paintball formulation), and two products appeared to alter the relative composition of scolytid species that attacked at two heights; however, tree mortality was unaffected. In trees challenged with semiochemical attractants, mortality ranged from 54% (4AA released from vials) to 82% (untreated and paintball application of 4AA). Although 4AA consistently reduces catch of D. frontalis in traps, it was not efficacious for protecting individual loblolly pines over a period of 30 or 60 days in this experiment.