Variation of B. dorsalis wing size parameters across the melanic morphs
We found a significant variation of the wing length, wing width, wing area, wing centroid size and wing loading across the four melanic morphs of B. dorsalis (Table 1). The sex factor only affected the centroid size parameters. Flies from morph 2 and 3 had larger wing length (Fig. 3A.i), width (Fig. 3A.ii), area (Fig. 3A.iii) and centroid size (Fig. 3A.iv) as compared to those from morph 1 and 4. Flies from morph 4 possessed a smaller weight (Fig. 3A.v) and wing loading (Fig. 3A.vi). The first two dimensions that accounted for 95.9 % of the total wing size variation did not separate the four morph of B. dorsalis (Fig. 3B). Nonetheless, we observed a positive correlation between all the wing size parameters; with length, width, area, and centroid size being strongly related (Fig. 3B).
Table 1. Two factors analysis of variance table showing the variation of wing size and individual weight across the four groups ofB. dorsalis studied.