FORECASTING CODLING MOTH PHENOLOGY BASED ON PHEROMONE TRAP CATCHES AND PHYSIOLOGICAL TIME MODELS

The relationship of pheromone trap catch to emergence and oviposition of the codling moth was defined for the 2-generation climate of Michigan [USA]. Catch anticipated emergence and oviposition during spring flight when the trap displayed greatest efficiency, but lagged behind emergence and closely followed oviposition during the F2. Trapping efficiency declined towards the end of the F1 and was generally lower during summer flight. Factors which possibly relate to this efficiency loss are discussed. First catch and the catch peaks in both generations were evaluated as reference points for the prediction of phenological events (particularly egg hatch) in both generations. Of 4 forecasting methods, degree day and developmental unit summations, starting from first catch, for the preoviposition and incubation period were most reliable in predicting the beginning of spring brood egg hatch.