Fig 2. Pictures of left wings (a), left eye cornea (b) and dorsal area facets (c) from a B. eunomia female.

Arrows in panel (a) indicate points between which wing length was measured: base and end of the R4 and M1 veins. In panel (b) we indicated the four different regions of the eye on the butterfly head (right picture) and on the cornea (i.e. D: dorsal, F: frontal, L: lateral and V: ventral regions) and an illustration of the way the eye area was measured (black line surrounding the four regions of the eye). In panel (c), we indicated two examples of measures of facet size, quantified on rows of five facets.