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 Rower thrips,Frankliniella occidentalis(Pergande).F. occidentalisreadily fed and oviposited on nonflowering romaine lettuce,Lactuca sativassp.longifoliaLam. Cheese weed,Malva palvifloraL. and burdock (gobo),Arctium lappaL. were likewise more preferred for oviposition compared with jimson weed,Datura stramoniumL. or golden crown-beard,Verbesina enceloides(Cav.) Benth&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 withM. palviflora=V. enceloides>D. stramonium=L. sativa. The mean proportion of immatures completing development to adults was greatest at higher temperatures. Leaf suitability forF. occidentalisdevelopment was ranked asL. sativa>M. palviflora=D. stramonium>V. enceloides=A. lappa.Implications of results in tomato spotted wilt tospovirus epidemiology are discussed.