Fig. 4. Composite images of species from the nymphalid subfamily Heliconiinae, genus Heliconius. (A) H. melpomene, (B) H. charitonius, (C) H. cydno, (D) H. sapho, (E) H. hewitsoni, (F) H. cydno chioneus. In contrast to the depolarized patterns typical of open areas shown in A and B, C–F show a series of forest living co-mimics, each with polarized blue iridescent scales covering much of the wing surface. Variable white or yellow `windows' of pigmented scales reflect depolarized light. Heliconius cydno (C,F) is a close sister species with H. melpomene (A), showing the stark contrast that can arise between related butterflies living in dramatically different light environment. False-color portions of the images are coded as in Figs 1 and 3.