FLIGHT ACTIVITY AND OVARIAN DYNAMICS OF THE YELLOW WOOLLYBEAR, SPILOSOMA-VIRGINICA (F) (LEPIDOPTERA, ARCTIIDAE), IN IOWA

Despite the occasional importance of the yellow woollybear, Spilosoma virginica (F.), as a pest of soybean, Glycine max, relatively little i s known about its biology in the Midwest. The objective of this six-ye ar study was to describe flight activity and ovarian dynamics of the a dult yellow woollybear in Iowa. In most years, initial flight activity occurred by mid-April and continued until mid to late October. In all years, ovipositional-class females were the most prevalent females ca ptured. Preovipositional and postovipositional females were not well r epresented in trap catches. Periods of flight activity were similar am ong years, consisting of two periods each year. The first activity per iod occurred between approximately 15 April and 30 June, with reduced activity during late June and early July. The second major flight peri od began approximately 1 July and ended from 25 September to 26 Octobe r, depending on the year. Adult flight activity and ovarian dynamics i ndicated that at least three generations were produced annually. Two c omplete generations developed during late spring and summer, and pupae from the third generation overwintered.