Fig. 6. Hansson's histochemical stain of isolated adult female mosquito midguts. Histochemistry indicates that the enzyme is localized in the midgut of all the species with various degrees of darkening. The enzyme also appears to be associated preferentially with the posterior midgut (black arrows) in several of these species when compared to the anterior midgut (red arrows). (A) Cx. nigripalpus, (B) An. quadrimaculatus, (C) Ae. albopictus, (D) Cx. quinquefasciatus, (E) Ae. aegypti, (F) Oc. taeniorhynchus. Scale bars, 500 µm.