PREFERENCES AND DEVELOPMENT OF WESTERN FLOWER THRIPS (THYSANOPTERA, THRIPIDAE) ON PLANT HOSTS OF TOMATO SPOTTED WILT TOSPOVIRUS IN HAWAII

Five important plant hosts of tomato spotted wilt tospovirus at two phenological stages were assayed in the laboratory to determine the host preference of adult western flower thrips, Frankliniella occidentalis (Pergande). F. occidentalis readily fed and oviposited on nonflowering romaine lettuce, Lactuca sativa ssp. longifolia Lam. Cheese weed, Malva palviflora L. and burdock (gobo), Arctium lappa L. were likewise more preferred for oviposition compared with jimson weed, Datura stramonium b. or golden crown-beard, Verbesina enceloides (Cav.) Benth and Hook. ex Gray. The following order of feeding or oviposition preference for plants in the vegetative stage was observed: L. sativa > A. lappa = M. palviflora > D. stramonium = V. enceloides. Preference changed at plant flowering with M. palviflora = V. enceloides > D. stramonium = L. sativa. The mean proportion of immatures completing development to adults was greatest at higher temperatures. Leaf suitability for F. occidentalis development was ranked as L. sativa > M. palviflora = D. stramonium > V. enceloides = A. lappa. Implications of results in tomato spotted wilt tospovirus epidemiology are discussed.