The heat-driven phenology model used for initiating codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), management in Washington state was examined to determine the need for using the capture of the Þrst moth as a method of synchronizing the model and phenology of Þeld populations (ϭbioÞx). We examined trap catch data taken at 1Ð2-d intervals from two research orchards; one data set encompassed a 28-yr period and the other data set a 4-yr period. We also examined consultant-collected

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... data taken at 7Ð10-d intervals from 15 sites (N ϭ 81), mostly between 2001 and 2005. At the two research sites, we found the mean bioÞx occurred at 96 degree-days (DD) (DD Celsius by using 10ЊC lower threshold and 31.1ЊC horizontal upper threshold) after 1 January (SD ϭ 14.4; min. ϭ 68, max ϭ 122). After correcting for longer sampling intervals in the consultant data set, the bioÞx at the nonresearch sites occurred at 97 DD (N ϭ 50, SD ϭ 14.4; min. ϭ 74, max ϭ 120), nearly identical to that at the research sites. We also examined the performance of the codling moth model at predicting moth ßight and egg hatch using a bioÞx and by just accumulating heat units from 1 January. The model performance was similar in both generations regardless of whether a bioÞx was used. The elimination of bioÞx simpliÞes management and eliminates mistakes associated with poor trap catch, particularly in low-pressure situations where mating disruption reduces trap efÞciency.