Effectiveness of esfenvalerate, cyfluthrin, and carbaryl in protecting individual lodgepole pines and ponderosa pines from attack by Dendroctonus spp.

The effectiveness of registered and experimental application rates of insec ticides esfenvalerate (Asana XL), cyfluthrin (Tempo WP and Tempo 2), and ca rbaryl (Sevimol and Sevin SL) was assessed for protection of individual hig h-value lodgepole pines from mountain pine beetles in Montana and ponderosa pints from western pine beetles in Idaho and California. This field test w as conducted on the Deerlodge National Forest in Montana, the Boise Nationa l Forest in Idaho, and the Eldorado National Forest in California. The bole s of the trees were treated with a candidate insecticide treatment to a hei ght of about 10 m, the surface likely to be attacked by the bark beetles. T o challenge the treatments, beetle attack densities were enhanced by using aggregation pheromones of the appropriate Dendroctonus species. One applica tion of esfenvalerate at 0.025 percent protected lodgepole pines from mount ain pine beetle for one summer, but not a second summer. Cyfluthrin applied once at 0.025 percent protected lodgepole pines for one summer and at 0.05 percent was effective for a second summer. One application of either carba ryl formulation at I percent protected lodgepole pines for two summers. Esf envalerate at 0.012 percent protected ponderosa pines in Idaho for one summ er; however, one application of esfenvalerate at 0.025 percent was ineffect ive in protecting trees far a second summer. A single application of cyflut hrinn at 0.025 percent was effective for one summer, whereas a similar trea tment with 0.1 percent cyfluthrin, in either the Tempo WP or Tempo 2 formul ations, was effective for 16 months or two summers. One treatment with carb aryl at 2 percent was effective for the 4 summer months; only the Sevin SL formulation appeared to be effective for the second summer in Idaho. Esfenv alerate was applied once at 0.025 percent and 0.05 percent in California an d protected ponderosa pines from western pine beetles for a full summer. Ne ither esfenvalerate treatment was effective for a second summer. Cyfluthrin was applied to ponderosa pines in California at the reduced concentrations of 0.0028 percent, 0.008 percent, and 0.025 percent. None of these treatme nts protected these trees from induced attack by western pine beetle far on e summer.