Western Flower Thrips Can Transmit Tomato spotted wilt virus From Virus-infected Tomato Fruits
In this study, we demonstrate that western flower thrips (WFT, Frankliniella occidentalis) can acquire and transmit Tomato spotted wilt virus (TSWV) from symptomatic tomato fruits. TSWV and other thrips-transmitted tospoviruses have long been known to spread via plant propagation material such as transplants. Global dissemination of tospoviruses has also been linked, in part, to transport and trade of thrips-infested and virus-infected horticultural products. However, the role of tomato fruits transported across state and national borders has not previously been examined as a means of virus spread or as a source for thrips acquisition of virus. Tomato fruits displaying typical tospovirus symptoms were purchased from several Washington State grocery stores. Many of these symptomatic fruits tested positive for TSWV and some for Pepino mosaic virus (PepMV). First instar larvae of WFT successfully acquired TSWV from these infected tomato fruits and transmitted the virus as adults to Emilia sonchifolia plants. Symptomatic E. sonchifolia plants were confirmed positive for TSWV by lateral flow immunoassays and sequence analysis of a portion of the nucleocapsid gene. These results suggest the dissemination of TSWV (and likely other tospoviruses) and PepMV to new geographic areas by human-assisted transport of infected tomato fruits.