Ultrastructure of the flight muscle of worker honey bees heavily infested by the tracheal mite Acarapis woodi

Abstract - Worker honey bees, heavily infested with tracheal mites, were collected in Vacaville, CA during the summer of 1988 and spring of 1989. The dorsal longitudinal indirect flight muscle of both healthy and heavily infested worker honey bees was studied by transmission electron microscopy. In the flight muscle of healthy honey bees, mitochondria were large and arranged in rows between the myofibrils. Glycogen particles were embedded in the myofibrils and accumulated in the sarcoplasm. In the flight muscle of tracheal mite-infected honey bees, glycogen particles were completely depleted and both the cristae, inner and outer membranes of the mitochondria, as well as the myofibrils, were electron-dense. The sarcoplasm of the flight muscle was electron-lucid. The significance of these ultrastructural changes is discussed in relation to tracheal infestation.