The CAT activity in the first to fifth instars of S. frugiperda infected by B. bassiana PfBb was significantly different over infection time, with a peak at 36, 12, 24, 24, and 60 h, respectively (F5,12 = 10.76, 10.30, 6.91, 5.17, and 3.32, respectively; p < 0.05); however, CAT activity in the sixth instar did not vary over the infection time (F5,12 = 1.82, p = 0.184) (Figure 5). This evidence concerns the gene CAT and infection.