Use of historical temperature data for timing insecticide applications of the Nantucket pine tip moth (Lepidoptera: Tortricidae): evaluation of damage and volume increment efficacy

Abstract

Abstract The effectiveness of optimal spray period intervals based on mean daily temperatures were evaluated as a spray‐timing tool to control high density populations of the Nantucket pine tip moth Rhyacionia frustrana (Comstock). Initial tree growth realized from first generation R. frustrana control was compared to that from conventional applications of one insecticide treatment scheduled for each of three annual generations. The optimal spray period intervals provided by Fettig et al. (2000a) were highly effective for controlling R. frustrana infestations. The control group averaged 47.0 ± 2.2% whole tree damage for all sites and generations as compared to 0.6 ± 0.2% for the treated group. Volume gains attributable to R. frustrana control averaged 16.9%, 46.4% and 98.6% for first generation control, and 46.6%, 72.7% and 146.3% for conventional applications of one insecticide treatment scheduled for each of three annual R. frustrana generations at Northampton, Halifax I and Halifax II, respectively. Growth returns increased as mean damage estimates increased for both treatments, suggesting that returns realized from a single, first generation application are likely to increase with population density.