Objective To study the control effect of 7 insecticides on wheat aphids applied in ultra-low volume by plant protection drones under walnut-wheat intercropping system, so as to provide a scientific basis for the high efficient control.

Methods Field trials have been conducted using the ultra-low volume stem and leaf spraying method by plant protection drones.

Results The population decline rate and control effect of 5% imidacloprid WP treatment showed higher under farmer household mode, but with the prolonging of application time, the population decline rates and control effects of 22% sulfoxaflor SC, 20% clothianidin SC and 22% thiamethoxam-lambda-cyhalothrin SC treatments gradually increased, which had no significant difference compared with 5% imidacloprid WP. 70% imidacloprid WG, 20% pymetrozine-clothianidin WG and 70% nitenpyram-buprofezin WG treatments showed lower population decline rates and control effects than that of 5% imidacloprid WP. The average control effects of suspension concentrate formulation were higher than that of water dispersible granule formulation on wheat aphids at the 1, 3 and 7 days after application, with percentages of 42.49%, 34.29% and 52.86%, respectively.

Conclusion It is recommended to choose insecticides of the suspension concentrate formulation when using plant protection drones to control wheat aphids. In this experiment, 22% flonicamid SC, 20% thiamethoxam SC, and 22% thiamethoxam-lambda-cyhalothrin SC showed better control effects on wheat aphids in the walnut-wheat intercropping fields.