Fig. 3. Wing-beat frequency (WBF; s^–1) of D. melanogaster as a function of flight temperature (T_test, °C), developmental temperature (T_dev, °C), body mass (A) and wing area (B). As test temperature increased, wing-beat frequency significantly increased (plots from left to right). Flies developing at cold temperatures (blue triangles, 15°C) had significantly lower wing-beat frequencies at every test temperature compared with flies developing at intermediate temperatures (orange circles, 23°C) or warmer temperatures (red squares, 28°C). Males (open symbols) and females (filled symbols) did not have significantly different WBFs after controlling for wing area and body size. Heavier flies tended to have faster WBFs (A; Table 2D), and flies with larger wings had slower WBFs (B; Table 2D) after statistically controlling for T_dev and T_test.