Evaluation of dissected digestive tracts by bioluminescent imaging . The whole gut from insects, evaluated in the third and fourth weeks after feeding (named 1, 2, 3, 4 and 5), were macerated. The parasites were counted in a Neubauer chamber and evaluated by the CCD camera in a 24 well plate (A, B). The photon radiance measured in each well of the plate was positively correlated to the parasite number, R = 0.895 (n = 11) (C). False negative insects were observed along the life cycle by bioluminescent imaging, due to D-luciferin diffusion and distribution throughout the insect body, in contrast with the dissected digestive tract (D). Parasites were counted in a Neubauer chamber and the numbers are displayed in the images (D).