Pyrifluquinazon baseline susceptibility and inhibition of Tomato chlorosis virus transmission by Bemisia tabaci

Background Tomato chlorosis virus (ToCV) is associated with tomato yellow leaf disorder diseases in more than 20 countries. ToCV can be transmitted in a semipersistent 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. Result 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 the feeding activities of B. tabaci. The antifeedant concentration of 50% (AFC50) values 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. Conclusion These results provided new information about the effects of modulators of the vanilloid‐type transient receptor potential channel on the toxicity to B. tabaci and inhibition of ToCV transmission. © 2023 Society of Chemical Industry. Pyrifluquinazon exhibited significant insecticidal activity and inhibiting effect on the feeding activity of Bemisia tabaci. Foliar application of pyrifluquinazon and afidopyropen effectively reduced the Tomato chlorosis virus (ToCV) transmission and suppressed the ToCV loads caused by B. tabaci.