Insecticide resistance monitoring of Nilaparvata lugens (Stål) to ten insecticides in the rice region of South China in 2023

In order to clarify the current resistance status of Nilaparvata lugens in the rice-growing areas of South China in 2023, the rice stem dipping method was adopted to monitor the resistance of 7 field populations of N. lugens in 4 provinces in South China to 10 commonly used insecticides. The results showed that N. lugens still had a high level of resistance to three pesticides that had been suspended for the control of this pest, namely buprofezin (876.2-5151.2 fold), imidacloprid (3534.0-9949.9 fold) and thiamethoxam (1253.8-2668.3 fold), and the resistance continued to show an upward trend. It had reached a moderate to high level of resistance to dinotefuran (49.4-482.5 fold), pymetrozine (77.2-351.3 fold), nitenpyram (16.6-106.4 fold) and chlorpyrifos (20.7-105.3 fold), and had a moderate level of resistance to sulfoxaflor (13.2-46.0 fold). It had a sensitive to low level of resistance to triflumezopyrim (2.3-8.6 fold) and still remained at a sensitive level to etofenprox (1.0 fold). Therefore, it is recommended that insecticides with different action mechanisms such as triflumezopyrim and etofenprox can be used alternately to control N. lugens in the rice-growing areas in this region. The results can provide a reference for the management of field resistance of N. lugens.