Abstract
Attacks by Dendroctonus frontalis Zimmermann were prevented on southern pines by applications of lindane or chlorpyrifos to the entire bole and to the top half of the bole only. Treatment of the basal 2 m and the lower half of tree boles did not prevent attacks. By applying toxicants to only the top half of trees, insecticide volume was reduced by over 30%, and contamination of nontarget areas near the base of the trees was significantly reduced.