THE DEVELOPMENT RATES OF THE EGG AND PUPAL STAGES OF DROSOPHILA-MELANOGASTER (MEIGEN) UNDER CHANGING CONDITIONS OF TEMPERATURE AND HUMIDITY

1. The durations of development of eggs and pupae of Drosophila melano gaster (Meigen) (Diptera: Drosophilidae) were measured under two sets of changing conditions of temperature and humidity in the laboratory. 2. In the first set, temperature and humidity were left to change regu larly every 12 h, mean developmental times of both stages were general ly the same as expected for constant conditions. 3. In the second set, where the two factors were left to vary in an irregular fashion, deve lopmental durations for both stages were still virtually the same as u nder constant conditions. 4. A computer model was constructed on the b asis of the developmental durations of these stages under constant con ditions, this was used to predict and measure any deviation in their d evelopment under the above mentioned alternating conditions from that expected under constant ones.