DETECTION OF TOMATO SPOTTED WILT VIRUS IN TOBACCO THRIPS (THYSANOPTERA, THRIPIDAE) OVERWINTERING IN HARVESTED PEANUT FIELDS

Volunteer and transplanted peanut, Arachis hypogaea L., and cutleaf evening primrose, Oenothera laciniata Hill, were sampled for thrips, Frankliniella spp., from November 1990 to April 1991 in seven fields in southwestern Georgia that had been planted with peanut during 1990. Thrips and roots from these plants were assayed for presence of tomato spotted wilt virus with enzyme-linked immunosorbent assay. Totals of 1,414 brachypterous and 2,360 macropterous tobacco thrips, Frankliniella fusca (Hinds), 218 western flower thrips, Frankliniella occidentalis (Pergande), and 8,590 Frankliniella spp. larvae were assayed during the study. The virus was repeatedly detected in adult tobacco thrips and thrips larvae collected from three fields. Virus incidence ranged from 0 to 6.2% in brachypterous adults, 0 to 10.0% in macropterous adults, and 0 to 0.9% in thrips larvae, depending on field and sample date. Tomato spotted wilt virus also was detected in two adult western flower thrips. The virus was detected in only 2 of 816 volunteer peanut roots and in none of 374 cutleaf evening primrose roots assayed during March and April. Implications for overwintering by tomato spotted wilt virus are discussed.