关键词: 亚洲玉米螟, 红绶曲霉, 酰胺类杀虫剂, 相容性, 联合毒力, 增效作用

Abstract: 【Aim】 To clarify the compatibility of Aspergillus nomius ACB1042 with four amide insecticides and the joint toxicity to Ostrinia furnacalis after mixing. 【Methods】 The recommended field concentrations of four amide insecticides, 20% chlorantraniliprole suspension concentrate (SC), 10% cyantraniliprole oilmiscible flowable concentrate (OF), 10% tetrachlorantraniliprole SC and 20% tetrazolfenamide SC, were used as the initial concentrations, and the effects of the four insecticides on the spore germination inhibition rate, inhibition rate of mycelial growth and sporulation inhibition rate of A. nomius ACB1042 were measured by hemocyte counting and crossover methods, respectively. The median lethal concentration (LC₅₀) values of A. nomius ACB1042 and 20% tetrazolfenamide SC against the 3rd instar larvae of O. furnacalis by spraying method as well as the indoor joint toxicity of a mixture of LC₅₀ of A. nomius ACB1042 and LC₅₀ of 20% tetrazolfenamide SC treatments in the volume ratios of 9∶1, 4∶1, 1∶1, 1∶4 and 1∶9 against the 3rd instar larvae of O. furnacalis, and the activities of peroxidase(POD), superoxide dismutase(SOD), catalase(CAT), polyphenol oxidase (PPO), carboxylesterase(CarE) and glutathione S-transferase(GST) in the 3rd instar larvae of O. furnacalis treated with LC₅₀ of 20% tetrazolfenamide SC and LC₅₀ of A. nomius ACB1042 in the mixture of 4∶1 volume ratio at 24, 48, 72, 96 and 120 h after treatment were determined. 【Results】 The four insecticides had certain inhibitory effects on the spore germination rate, mycelial growth rate and sporulation of A. nomius ACB1042 at the recommended field concentration, and the inhibitory effects were weakened with the increase of insecticide dilution fold, among which, 20% tetrazolfenamide SC 10-fold dilution concentration(0.1 RC) had a better compatibility with A. nomius ACB1042, with the germination inhibition rate, the sporulation inhibition rate, and the inhibition rate of mycelial growth for 9 d of 0, 2.15% and 0.78%, respectively. The co-toxicity coefficients (CTCs) of A. nomius ACB1042 and 20% tetrazolfenamide SC in different volume ratios were all greater than 120, and the mixture of 20% tetrazolfenamide SC and A. nomius ACB1042 in the volume ratio of 4∶1 had the best synergistic effect, with the LC₅₀ value of 2.359 mg/L against the 3rd instar larvae of O. furnacalis, and the CTC was as high as 365. The activities of POD, SOD, CAT, PPO, CarE and GST in the 3rd instar larvae of O. furnacalis after treatment with the mixtures of A. nomius ACB1042 and 20% tetrazolfenamide SC showed a trend of increasing and then decreasing. 【Conclusion】 In field control of O. furnacalis, A. nomius ACB1042 can be mixed with 20% tetrazolfenamide SC at low concentrations to achieve synergic effect.

Key words: Ostrinia furnacalis, Aspergillus nomius, amide insecticides, compatibility, joint toxicity, synergistic effect