The immature stages of the parasitoid Muscidifurax uniraptor Kogan & Legner were morphologically characterized. House fly pupae, 48 to 72-hour old, were exposed to adult parasitoids in laboratory conditions (25 ± 1ºC, 70 ± 10% R.H. and 14 h of photophase) for 18-hour period. Daily, samples of these pupae were dissected for observation of the immatures. Measurements of larval cephalic capsules and electromicrographies of the immatures were made with a scanning electron microscope. M. uniraptor presents four instars wich are very similar in shape and motion, but different in size and volume, and presents a gradual loss of transparency. During the egg to adult development, different stages or larval instars occurred simultaneously.
Insecta; pupal parasitoid; house fly