Efficacy tests and determination of optimal spray timing values to control nantucket pine tip moth (Lepidoptera: Tortricidae) infestations.

The Nantucket pine tip moth, Rhyaciona frustrana (Comstock), a common regeneration pest of loblolly pine, Pinus taeda L., has been shown to reduce tree volume yields through larval feeding. Chemical applications can be effective in protecting trees from the growth losses associated with this feeding, and optimum spray timing values are commonly used to reduce the number of necessary applications and to increase insecticide efficacy. Optimal spray timing values for the Georgia Piedmont were obtained for the following four insecticides available for use in loblolly pine plantations: permethrin (Pounce), lambda-cyhalothrin (Warrior T), spinosad (SpinTor 2 SC), and Bacillus thuringiensis variety kurstaki Berliner (Foray 48B). Optimal timing values were similar between the first and second generations for each of these compounds. All of the insecticides used in this study significantly reduced tip moth damage below the control treatment levels. Lambda-cyhalothrin was the most efficacious and had the longest spray timing window. B. thuringiensis was the least effective and had the shortest timing window. Spinosad and permethrin were similar in efficacy and spray timing values. This information is applicable to regions where there are three tip moth generations per year, as found in the southern Piedmont region and the coastal plain of Virginia and most of North Carolina.