Studies on Rhinoestrus purpureus (Diptera: Oestridae) larvae infesting donkeys (Equus asinus) in Egypt. III. Pupal duration under controlled conditions.

The pupal duration of Rhinoestrus purpureus was studied under variable degrees of temperature and relative humidity (RH). It was found that pupal duration was affected by temperature but not by RH. An increase in the temperature above 22 degrees C decreased the pupal duration: 26-27 days at 22 degrees C, 16-24 days at 27 degrees C, 13-15 days at 32 degrees C. At 37 degrees C, the pupated larvae failed to pupate and died. The deformity ratio of emerged flies was 25-30% at 22-32 degrees C, but it was directly proportional to RH at a constant temperature of 32 degrees C: 26.1% at 75% RH, 16.7% at 50% RH, 6.7% at 30% RH. It was concluded that the optimum temperature and RH for obtaining normal active flies were 32 degrees C and 30%, respectively.