Scanning Electron Microscopy of Developmental Stages of Malpighamoeba mellificae Prell in the Honey Bee

Primary trophozoites of Malpighamoeba mellificae Prell in the process of penetrating the cell membrane were found among the brush border of epithelial cells of the midgut of Apis mellifera L. They were long and slender with an average diameter of 3.68 μm. Their surfaces had some wrinkles and the cytoplasm contained some vesicles. Secondary trophozoites were found in the lumen of Malpighian tubules. Their size was variable and their shapes were highly irregular; some had pseudopodia. The smooth surface of trophozoites possessed numerous small protrusions and pits. Mature cysts were small and oval-shaped; they measured from 2.65 times 3.62-3.4 times 4.6 μm. Their surface was usually smooth but some had wrinkles.