Transmission of capsicum chlorosis virus by Thrips palmi (Thysanoptera: Thripidae)

Transmission efficiencies of capsicum chlorosis virus (CaCV) were investigated for four thrips species (Thysanoptera: Thripidae), Frankliniella occidentalis (Pergande), Frankliniella intonsa (Trybom), Thrips palmi (Karny), and Thrips tabaci Lindeman infesting green pepper in Japan. The first-instar larvae of the thrips were allowed to feed on CaCV-infected green pepper leaves for 24 h. The transmission of CaCV by thrips was examined using a petunia leaf disk assay. CaCV was transmitted by four male (8.70%) and four female (3.88%) T. palmi, but the virus was not transmitted by adults of any other species. In a second transmission assay, 10 adult T. palmi that had fed on infected leaves as larvae were released to healthy green pepper seedlings. After 21 days, the seedlings were examined and 50% of them showed symptoms of CaCV infection. RT-PCR confirmed that they were infected with the virus. The viruliferous rate of adult T. palmi was 60%, while CaCV was not detected in adults of the other three species. These results suggest that T. palmi is capable of being a new vector of CaCV.