Field-based phenological model predicts pink bollworm emergence

Control of pink bollworm, a serious pest of cotton in southeastern California, is enhanced by knowing when the different stages of its development will occur. Prediction of pink bollworm development requires a phenological model that relates development to a thermal scale. For spring emergence, the study showed that heat unit accumulation starting Feb. 1 was the best predictor of beginning and peak emergence. This research used field-collected data to establish lower and upper temperature thresholds of 57 degree and 91 degree F (13.9 degree and 32.8 degree), respectively; 409 degree and 918 degree F-days (227 degree and 510 degree C-days) from Feb. 1 to the beginning and the peak of spring emergence, respectively; and 866 degree F-days (492 degree C-days) between generations, from adult moth to adult moth