The flies were reared from natural infested guava
fruits (Psidium guayava) collected in Jundiaí (SP). The
digestive tracts of adult males and females of A. fraterculus
(Wiedemann) and females of C. capitata (Wiedemann)
were removed in insect physiological saline using a
stereomicroscope, fixed in Bouin solution for 24 h and then
transferred to 70% ethanol. The tissues were subsequently
dehydrated in an acetone series (70-100%), dried in a
Balzers critical point drying apparatus and mounted on
aluminum holders prior to coating with carbon and gold
in a Balzers Sputtering apparatus. All preparations were
analyzed and photographed using a Jeol P-15 scanning
electron microscope and Neopan 200 film.