Long-term experiment showing phenoloxidase activity in the midgut of
. PO activities were measured in the anterior midgut of R. prolixus 5th instar nymphs at 7 and 12 days after feeding on blood without parasites. Previously, 4th instar nymphs were fed on inactivated blood with or without 1 × 106 epimastigotes/mL. Treatments: white columns – control, uninfected group; black columns – infected group. Bars represent mean ± SEM of three independent experiments each with five insects (n = 15). Means were compared using Student T-test; ***p < 0.001 and **p < 0.01.