OVERWINTERING HOSTS AND WINGFORM OF THRIPS, FRANKLINIELLA SPP IN GEORGIA (THYSANOPTERA, THRIPIDAE) - IMPLICATIONS FOR MANAGEMENT OF SPOTTED WILT DISEASE

Forty-five plant species were surveyed for thrips during the winter and spring in Georgia. The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), was collected from 44 plant species, and the tobacco thrips, Frankliniella fusca (Hinds), was collected from 25 plant species. Adults of both species were 60-100% female in most samples. Thrips larvae were collected from 37 plant species, but were relatively uncommon until mid-March. Western flower thrips and tobacco thrips were most abundant during the spring on Trifolium spp. and volunteer peanut, Arachis hypogaea L., respectively. Volunteer peanut was intensively sampled for thrips during the fall and spring. Adults were 60-95% tobacco thrips in most samples, with western flower thrips comprising the remainder. Thrips larvae were collected in all samples, but were more numerous during the spring. Adult tobacco thrips were predominantly brachypterous during the late fall and early spring, suggesting that some populations of tobacco thrips overwinter in old peanut fields. Brachypterous adults were rarely observed on peanut transplanted during the late March into an old pearl millet, Pennisetum americanum (L.), field, but were common on peanut transplanted into an adjacent old peanut field. The potential of tobacco thrips, western flower thrips, and their plant hosts as winter reservoirs for tomato spotted wilt virus (TSWV) is discussed. Destruction of overwintering thrips, volunteer crops, and winter annual weeds in cultivated fields is suggested as a potential strategy for TSWV management.