Predicting Seasonal Flight of European Pine Shoot Moth (Lepidoptera: Tortricidae) in Western Oregon

A linear regression model for predicting pheromone trap catch of male European pine shoot moth, Rhyacionia buoliana (Denis & Schiffermuller), based on accumulated heat units is presented. The model was developed from 3 yr of maximum–minimum air temperature and pheromone trap data collected in western Oregon during 1986–1988. Data collected the following years, 1989–1990, were used to evaluate the model. A lower threshold (base) temperature of −2.2°C was used in calculating daily degree-days since 1 January. The model successfully predicted accumulated male moth catch to within 1–3 d during 1989. Predicted degree-day requirements (above −2.2°C) are 1,712 for 10% catch, 1,958 for 50% catch, and 2,205 for 90% catch.