Interaction of Temperature and Feeding Rate in Determining the Rate of Development of Larval Culex tarsalis (Diptera, Culicidae)1

The duration of larval stages (logarithm) of Culex tarsalis Coquillett shows a linear relationship to feeding rate (logarithm) at 20° and 30°C. At the feeding rates at which larvae can complete development in 12, 14, 16, 18, 20, 22, or 24 days, they use 87, 83, 78, 74, 69, 62, or 52% more food at 20°C than they do at 30°C. Pupae were 12 and 18% heavier at 20°C than they were at 30°C. At 0.1, 0.2, 0.4, and 0.8 mg per larva per day the larval developmental time was 5.5, 6.7, 7.8, and 8.1 days shorter at 30°C than at 20°C. The shortening of the duration of larval stages at 30°C over 20°C was accompanied by a greater decrease in the duration of stages I and III than of stages II and IV.