FORECASTING FLIGHT ACTIVITY OF SPARGANOTHIS-SULFUREANA (LEPIDOPTERA, TORTRICIDAE) IN CRANBERRIES

The first seasonal flight of male Sparganothis sulfureana was monitore d with pheromone traps in a Wisconsin cranberry bed, and the dates of first catch and 50% catch were recorded. The number of days from first catch to 50% catch varied less than accumulated degree-days from firs t to 50% catch. A Weibull function was used to model cumulative percen tage capture as a function of days after first catch. Predictions by t he function were evaluated with data sets from locations in Wisconsin, Massachusetts, and New Jersey. The function predicted 50% catch withi n a mean of less than a day, and the error of the predictions had a st andard deviation of 3.9 d in Wisconsin. The Wisconsin model tended to predict late in other states, thus alternative models are proposed.