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

The Nantucket pine tip moth, Rhyaciona frustrana (Comstock), a common regen eration pest of loblolly pine, Pinus taeda L., has been shown to reduce tre e volume yields through larval feeding. Chemical applications Mn be effecti ve in protecting trees from the growth losses associated with this feeding, and optimum spray timing values Ne commonly used to reduce the number of n ecessary applications and to increase insecticide efficacy. Optimal spray t iming values for the Georgia Piedmont were obtained for the following four insecticides available for use in loblolly pine plantations: permethrin (Po unce), lambda-cyhalothrin (Warrior T), spinosad (SpinTor 2 SC), and Bacillu s thuringiensis variety kurstaki Berliner (Foray 48B). Optimal timing value s were similar between the first and second generations for each of these c ompounds. 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. thuringien sis was the least effective and had the shortest timing window. Spinosad an d permethrin were similar in efficacy and spray timing values. This informa tion is applicable to regions where there are three tip moth generations pe r year, as found in the southern Piedmont region and the coastal plain of V irginia and most of North Carolina.