LAUSR

BACKGROUND Tomato chlorosis virus (ToCV) is associated with tomato yellow leaf disorder diseases in more than twenty countries. ToCV can be transmitted in a semi-persistent manner by whitefly vectors such as Bemisia tabaci. Controlling the vector pests by using chemical insecticides is an efficient and effective approach to reduce and interrupt the virus transmission. Pyrifluquinazon is a new pyridine azomethine derivative, showing insecticidal toxicity to sucking pests by disturbing their feeding behavior. However, limited attention has been paid to the performance of pyrifluquinazon against B. tabaci and ToCV transmission. RESULTS This study showed the lethal concentration of 50% (LC50 ) values of pyrifluquinazon to 22 B. tabaci field populations ranged from 0.54 to 2.44 mg L-1 , and the baseline susceptibility of B. tabaci to pyrifluquinazon was 1.24 mg L-1 with a 95% confidence limit of 0.35 - 1.85 mg L-1 . Pyrifluquinazon and afidopyropen did not show cross-resistance to dinotefuran and pymetrozine in B. tabaci, which both inhibited feeding activities of B. tabaci. The antifeedant concentrations of 50% (AFC50 ) at 48 h were 0.70 mg L-1 for pyrifluquinazon and 2.13 mg L-1 for afidopyropen. Foliar application of pyrifluquinazon and afidopyropen reduced the ToCV transmission by 40.91% and 33.33%, respectively and significantly decreased the ToCV loads in tomato plants under laboratory conditions. CONCLUSIONS These results provided new information about the effects of modulators of the vanilloid-type transient receptor potential (TRPV) channel on the toxicity to B. tabaci and inhibition of ToCV transmission. This article is protected by copyright. All rights reserved.