REVISION OF A TIMING MODEL FOR CHEMICAL CONTROL OF THE NANTUCKET PINETIP MOTH (LEPIDOPTERA, TORTRICIDAE) IN THE SOUTHEASTERN COASTAL-PLAIN

The Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidopt era: Tortricidae), is a common pest of Christmas tree and commercial p ine plantations in the eastern United States (Yates et al. 1981). Duri ng the mid-1980's, a spray timing model for contact insecticides was d eveloped to predict optimal spray dates for controlling R, frustrana i n the southeastern Coastal Plain (Gargiullo et al. 1985). Although the model provided for generally acceptable control, analysis of the orig inal degree-day predictions revealed that some errors occur in degree- day accumulation values used to predict insecticide spray dates. We re port here the corrected values for both within-generation and cumulati ve year-long spray date predictions to control R. frustrana in locatio ns where four generations occur annually in the southeastern United St ates. A similar model for the Piedmont region of Georgia where three g enerations occur annually accurately predicts spray dates in its curre nt version (Gargiullo et al. 1983).