Abstract: Matsuda （Empoasca onukii）, Quaintance （Aleurocanthus spiniferus） and Boyer （Toxoptera aurantii） are three most common piercing-sucking insects in tea plantations, which severely reduce tea production and quality. Chemical control is one of the most important strategies in control of these tea pests. In order to screen high-efficient insecticides, the toxicities of 16 insecticides of ten different classes to the nymphs of three tea pests were evaluated under laboratory conditions. The results of toxicity tests showed that tolfenpyrad, emamectin, indoxacarb and chlorfenapyr showed the highest toxicities to the E. onukii nymphs, with the 24βh LC₅₀ values of 0.23, 0.52, 0.94βand 5.24βmg·L^-1, respectively. Cyantraniliprole, chlorantraniliprole, clothianidin and spirotetramat were four most toxic compounds for the A. spiniferus nymphs, with the 24βh LC₅₀ values of 0.15, 0.26, 0.41 and 0.66βmg·L^-1, respectively. Except for dinotefuran and indoxacarb, other fourteen tested insecticides showed high toxicities to the T. aurantii nymphs, with the 24βh LC₅₀ values below 10βmg·L^-1. The results of this study laid a foundation for selecting and applying insecticides according to the target pests, and also promoting the reduction of pesticides used in tea plantations.

Key words: Empoasca onukii Matsuda, Aleurocanthus spiniferus Quaintance, Toxoptera aurantii Boyer, toxicity of insecticide