By the separation and purification of pathogenic fungi from Chilo suppressalis Walker larva, 5 different fungi were screened The effect of different nutrition on the biological activity of fungi were explored and the toxicity to adults and nymphs of Bemisia tabaci and Nilaparvata lugens were measured The most toxic strains were selected and the biotypes were clear through preliminary identification The results showed that 5 species of fungi have high toxicity to the two insect pests, and the toxicity of A26 and Bbr14 strains are stronger than others After processing 9 days, the accumulative mortality of A26 strain on adults and nymphs of B tabaci was the highest, 84.69%, 77.62% respectively, the infection rate was 91.17%, 88.24% and the LT50 was 4.31 d, 4.87 d, both were the lowest After processing 10 days, the accumulative mortality of A26 strain on adults and nymphs of N lugens was 87.54%, 73.18%, the infection rate was 90.13%, 87.13% and the LT50 was 5.14 d The effect of Bbr14 strain was lower Identification results showed that A26 strain was Aspergillus, Bbr14 strain was Beauveria bassiana and the effects of different nutrition on the biological activity were difference These provided the basis for the biological control of pests and fermentation |