Overwintering Viruliferous Frankliniella occidentalis (Thysanoptera: Thripidae) as an Infection Source of Tomato spotted wilt virus in Green Pepper Fields.

Abstract

Populations of overwintering viruliferous Frankliniella occidentalis were evaluated in Tomato spotted wilt virus (TSWV)-affected green pepper fields in Bungo-Ohno City, Oita Prefecture, Japan. A survey of TSWV-infected weeds showed that the incidence of infection was low in weeds. Stellaria aquatica was infected frequently; however, the infections were considered secondary cases since S. aquatica appeared in the fields around late February to early March. In contrast, TSWV was frequently detected from green pepper fruits until they rotted. F. occidentalis primarily inhabited and reproduced on the green pepper fruits and moved to Lamium amplexicaule when the fruits rotted and subsequently spread to other weed species as young shoots or flowers appeared. The flying activity level of F. occidentalis rose in late February, and viruliferous F. occidentalis transmitted TSWV to green pepper plants. We concluded that TSWV-infected green pepper fruits discarded in greenhouses and fields are the major source of infection.