Abstract: 【Aim】 Apolygus lucorum (Meyer-Dür) (Hemiptera: Miridae) is a serious piercing sucking pest of Bt cotton in China. Currently, spraying organophosphates and pyrethroids has been widely accepted for A. lucorum management, while spraying neonicotinoids is not recommended due to their low contact toxicity. However, neonicotinoid insecticidal seed treatments effectively protect cotton from A. lucorum infestation until blooming stage. Therefore, an appropriate bioassay method needs to be developed to re-evaluate the toxicity of these insecticides to A. lucorum. 【Methods】 Two different types of bioassays, i.e., glass-vial and artificial diet toxicity bioassay, were used to assess the toxicities of 16 insecticides belonging to five chemical categories to the 3rd instar nymphs and adults of A. lucorum. 【Results】 The LC₅₀ values of neonicotinoid insecticides to the adults and nymphs of A. lucorum ranged from 337.97 to 496.03 μg/mL in the glassvial toxicity test, which were significantly higher than those of other classes of insecticides (0.28-207.26 μg/mL). However, the LC₅₀ values of the neonicotinoids to both adults and nymphs ranged from 0.01-1.08 μg/g in the artificial diet bioassay, which were equal to or lower than those of other classes of insecticides. 【Conclusion】 The results indicated that the ingestion toxicity of neonicotinoids is stronger than the contact toxicity to A. lucorum and these insecticides should be recommended to fight against this pest. The artificial diet test can be used as an alternative resistance monitoring method for neonicotinoids in the future.

Key words: Apolygus lucorum; neonicotinoids, toxicity, glassvial bioassay, artificial diet bioassay