Figure 2. Activity and pH optima for proteases in the gut, salivary gland and saliva of Nezara viridula.

(a) Total protease and specific protease activities: Azocasein was used as a general protease substrate. (b) pH optima for total protease activities: Total protease activity was assayed in different buffer systems from pH 4.0 to 10.0 using azocasein as substrate. Error bars indicate standard deviation. Treatments with different letters are significantly different (P ≤ 0.01; Student’s t-test).