Figure 6. Enzymatic scavenging of the reactive oxygen species H₂O₂ from early 5^th instar larval Heliothis virescens plasma reduces virucidal activity. PBS, No plasma control; Cat, catalase (100 U/ml) control; Cat+Plasma, catalase incubated with plasma; superoxide dismutase (100 U/ml) control; superoxide dismutase +Plasma, incubation of plasma with the enzyme superoxide dismutase (100 U/ml). The enzymes were added to diluted plasma samples before the addition of HzSNPV (letters indicate significant differences between treatments; n = 4, mean ± SEM).