Fig. 3

Bend probability and crawling speed of larval locomotion in the 11 Drosophila species at 24 °C and their relationship to habitat temperature of each species. A, B Plots of the speed of the centroid of larvae and the bend angle of D. melanogaster (A) and D. willistoni (B). Each point corresponded to a datum of a single larva of a species at a single time frame. Thick horizontal lines denoted the threshold between crawling and bending. C Bend probability of individual larvae of each species. D Crawling speed of individual larvae of each species. Sample numbers in C and D were as follows: Dvir: n = 24; Dmel: n = 24; Dmoj: n = 30; Dper: n = 27; Dpse: n = 19; Dsec: n = 21; Dwil: n = 18; Dere: n = 22; Dmau: n = 26; Dana: n = 22; and Dyak: n = 16. E Scatter plot of bend probability at 24 °C against crawling speed at 24 °C. The median ± sem was shown. The red line showed the linear regression function, and the shaded area represented the 95% confidence band. The point estimate of the Pearson correlation and its 95% confidence interval was − 0.76 and [− .94, − 0.30], respectively