CAT and infection: At 36 h post-infection (Figure 6), significant differences in the SOD and CAT activities of larvae were observed among each strain treatment group and the CK group (p < 0.05), with SOD activities decreasing in the order of Bb01, bio-21738, CGMCC3.2055, CK, BbZ1, and CFCC81428, and CAT activities in the order of Bb01, BbZ1, CFCC81428, CK, CGMCC3.2055, and bio-21738.