Revision of a timing model for chemical control of the Nantucket pine tip moth (Lepidoptera: Tortricidae) in the southeastern coastal plain

The Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), is a common pest of Christmas tree and commercial pine plantations in the eastern United States (Yates et al. 1981). During the mid-1980's, a spray timing model for contact insecticides was developed to predict optimal spray dates for controlling R, frustrana in the southeastern Coastal Plain (Gargiullo et al. 1985). Although the model provided for generally acceptable control, analysis of the original degree-day predictions revealed that some errors occur in degree-day accumulation values used to predict insecticide spray dates. We report here the corrected values for both within-generation and cumulative year-long spray date predictions to control R. frustrana in locations where four generations occur annually in the southeastern United States. A similar model for the Piedmont region of Georgia where three generations occur annually accurately predicts spray dates in its current version (Gargiullo et al. 1983).