Abstract: In order to explore biopesticides suitable for controlling tea grain moth （Agriophara rhombata Meyr.）, the leaf dipping method was used. Five biological pesticides, Empedobacter brevis, Bacillus thuringiensis, AcNPV·Bt, HearNPV and Spodoptera exigua nucleopolyhedrovirus were used to detect the toxicity of the 3rd instar larvae of tea cereal moth in the laboratory. The dead numbers of caterpillars after 24, 48, 72, 96 h were counted separately. The death rate, the revised death rate, LC₅₀, the toxicity regression equations, the correlation coefficient and the 95% confidence interval were calculated under different treatments. The results showed that the five biological pesticides had toxic effects on the third instar larvae of the tea grain moth, and the virulence of that under 500 times liquid treatment between 72 h and 96 h showed AcNPV·Bt> Bacillus thuringiensis >HearNPV> Empedobacter >Spodoptera exigua nucleopolyhedrovirus brevis. Bacillus thuringiensis, AcNPV·Bt and HearNPV were recommended as the first-choice agents for the next field efficacy verification.

Key words: biological pesticide, Agriophara rhombata, leaf dipping method, toxicity test