Quantitative Evaluation of Frontalure and Cacodylic Acid Treatment Effects on Within-Tree Populations of the Southern Pine Beetle12

Within-tree populations of Dendractonus frontalis Zimmerman were measured in untreated control trees, cacodylic acid-injected trees, and frontalure-baited trees. Effects of the treatments were compared to the controls for the mean density/100 cm2 of attacking adults, eggs, larvae, pupae-callow adults, and brood adults by using a life table format. Mathematical models were employed to describe the within-tree spatial distribution and mean density/100 cm2 of the various life stages. Cacodylic acid treatments, when compared to controls, resulted in reduced attack density, substantially greater mortality between the egg-larva and larva-pupa-callow adult stages, greater total generation mortality, and a much reduced increase ratio for the generation. Treatment effects were most pronounced in the basal portion of the tree. Statistically, the mean densities/100 cm2 of the various life stages measured were significantly different from controls. The mean densities of the various life stages/100 cm2 in trees baited with frontalure were not significantly different from controls. Mortality between life stages, total generation mortality, and the increase ratio for the generation all were essentially identical to controls.