TRANSMISSION OF TOMATO SPOTTED WILT VIRUS BY THE WESTERN FLOWER THRIPS TO WEEDS AND NATIVE PLANTS FOUND IN SOUTHERN ONTARIO

Weed species and native plants occurring in southern Ontario, grown from seed or collected from the field, were exposed in a growth room to natural transmission of tomato spotted wilt virus (TSWV) by the western flower thrips (WFT), Frankliniella occidentalis. These plants were assayed for TSWV by both enzyme-linked immunosorbent assay (ELISA) and bioassay on suitable indicators, and thrips reproduction was examined on plants susceptible to TSWV. Of 302 native plant species tested, 113 species representing 35 families were field susceptible to TSWV, 62 species of which are first reported hosts for this virus. Eighty-six percent of these plants were ovipository hosts for the WFT.