Abstract: Insecticidal activities of tetraniliprole, abamectin, spinetoram, lambda-cyhalothrin, chlorantraniliprole, and cyantraniliprole against Ostrinia furnacalis were evaluated by laboratory assay. The results showed that 5% abamectin had the highest toxicity to the 3 rd instar larvae of O. furnacalis, with an LC₅₀ of 0.325 mg/L, followed by 6% spinetoram and 20% tetraniliprole, with LC₅₀ values of 1.129 mg/L and 4.547 mg/L, respectively, while 20% lambda-cyhalothrin had the lowest toxicity, with an LC₅₀ of 47.342 mg/L. The compatibility of the above insecticides with Aspergillus tamari XJ-2 was determined, with tetraniliprole showing the best compatibility with A. tamari XJ-2. At 0.3 mg/L, the inhibition rates on the growth rate, sporulation, and spore germination of A. tamari XJ-2 were 16.47%, 31.54%, and 3.27%, respectively, followed by lambda-cyhalothrin, with inhibition rates of 28.37%, 39.96%, and 17.36%, respectively. Abamectin and chlorantraniliprole showed the poorest compatibility, with inhibition rates on growth rate, sporulation, and spore germination of 43.26%, 52.25%, and 63.86%, and 40.76%, 49.52%, and 65.32%, respectively. Laboratory mixture toxicity tests showed that tetraniliprole combined with A. tamari XJ-2 at different volume ratios（10:0, 9:1, 4:1, 1:1, 1:4, 1:9, and 0:10） all exhibited significant synergistic effects（toxicity ratio > 1）. Among them, the 4:1 ratio achieved the optimal comprehensive effect, with a co-toxicity coefficient as high as 339 and a toxicity ratio of 1.07. In the single-agent controls, the mortality rate of tetraniliprole（79.74%） was significantly higher than that of the XJ-2 single agent（50.68%）. Field trials showed that the combination of tetraniliprole and A. tamari XJ-2 reached the highest efficiency at 21 days post-treatment, with a corrected control efficiency of 87.20%, which was significantly higher than those of tetraniliprole alone（79.74%） and A. tamari XJ-2 spore suspension alone（50.68%）, and also superior to Metarhizium anisopliae CQMa421 suspension（51.80%） and Beauveria bassiana ZJU435 suspension（65.22%）. Furthermore, the combination of 20% tetraniliprole and A. tamari XJ-2 significantly prolonged the duration of field efficacy. Compared to tetraniliprole alone and A. tamari XJ-2 spore suspension alone, its efficiency at 49 days post-treatment was 10.24% and 23.82% higher, respectively, indicating that this combination can serve as an efficient strategy for the green control of O. furnacalis.

Key words: Aspergillus tamarii, compatibility, co-toxicity coefficient, field control efficacy