LAUSR

BACKGROUND Bemisia tabaci (Gennadius) is a serious agricultural pest in the world. Neonicotinoids are the most important new class of synthetic insecticides used in pest management of B. tabaci. However, B. tabaci developed resistance to various active ingredients of neonicotinoids after the long-term and widespread application. RESULTS Dinotefuran exhibited high toxicities against most B. tabaci field populations. One population (Din-R) with a high level of resistance to dinotefuran (255.6-fold) was first identified in the field. Din-R population exhibited medium to high level resistance to all the tested neonicotinoid insecticides and high-level resistance to spinetoram. Genetic inheritance analysis revealed the resistance to dinotefuran was incomplete recessive and polygenic. The synergist piperonyl butoxide (PBO) significantly increased the toxicity of dinotefuran to Din-R. The activity of P450 in the Din-R was 2.19-fold higher than that in the susceptible population. RNA Sequencing analysis showed twelve P450 genes were significantly up-regulated in the Din-R, in which CYP6DW5, CYP6JM1, and CYP306A1 exhibited over 3.00-fold higher expression in the Din-R by using RT-qPCR. Expression of eight P450 genes were obviously induced by dinotefuran, and CYP6DW5 showed the highest expression level. After knockdown of CYP6DW5 in Din-R, the toxicity of dinotefuran increased significantly. CONCLUSION P450 played a crucial role in the dinotefuran resistance of B. tabaci, and CYP6DW5 was involved in the resistance. These results provide important information for the resistance management of B. tabaci and improve our understanding of resistance mechanism of dinotefuran. This article is protected by copyright. All rights reserved.