Fig. 4
From: Wing spot in a tropical and a temperate drosophilid: C = C enrichment and conserved thermal response
The bar graphs represent the average wing pigmentation values corrected for wing size of 10 isofemale lines for both D. biarmipes and D. suzukii at three different growth temperatures (18°C, 23°C and 28°C). The wing pigmentation values for the left and right wings are shown in panel AC and BD, respectively. The trends indicate a linear decrease in the degree of wing pigmentation with increasing temperature. The differences in wing pigmentation for the left and right wing were found to be non-significant (D. biarmipes, p > 0.05; D. suzukii, p > 0.05). However, variation in the wing-spot pigmentation across temperatures was highly significant (p < 0.001). AU: arbitrary units. In D. biarmipes; wing pigmentation was the darkest (6.69 × 10−3 arbitrary units/ au) at the lowest temperature (18°C) compared to the intermediate (6.36 × 10−3 au) (23°C) and the highest (5.29 × 10−3 au) (28°C) temperatures. Similarly, in D. suzukii wing pigmentation was darkest (1.13 × 10−2au) at the lowest temperature (18°C) compared to the intermediate (9.16 × 10−3 au) (23°C) and the highest (6.79 × 10−3 au) (28°C) temperature. Therefore, wing pigmentation exhibits a negative correlation with temperatures in both D. biarmipes and D. suzukii