PREDICTION MODELS FOR FLIGHT ACTIVITY OF THE CRANBERRY GIRDLER (LEPIDOPTERA, PYRALIDAE) IN WISCONSIN

Cranberry girdler, Chrysoteuchia topiaria, was monitored with pheromon e traps in Wisconsin cranberry farms. Cumulative 50% capture was relat ed to degree-days after first catch using air or soil temperature. An air temperature of 0-degrees-C and soil temperature of 2-degree-C were chosen as base temperatures for calculation of degree-days because th ey yielded estimates with the lowest coefficients of variation. Weibul l functions were fitted to the relationship between cumulative percent capture and time or degree-days after first trap catch using air or s oil temperatures. The models that predicted the date of 50% capture we re evaluated with data from two other farms. Degree-days after first c atch using soil temperatures predicted 50% catch with less variability than calendar date or degree-days after thaw of ice, but not signific antly less variability than days after first catch or degree-days afte r first catch using air temperatures.