Fig. 4. First three principal component (PC) coefficients from analyses of the shape of reflectance spectra (see Fig.3) of the hindwings of female Polyommatus icarus. Solid lines, PC1; dashed lines, PC2; dotted lines, PC3. (A) White, underside. (B) Background coloration, underside. (C) Black, underside. (D) Orange, underside. (E) Orange, upperside. (F) Brown, upperside. For further details see Fig.3.