Structural characterization of <italic>Papilio kotzebuea</italic> (Eschscholtz 1821) butterfly wings.

The ‘plain black’ forewings and black with ‘red spot’ hindwings of the <italic>Papilio kotzebuea</italic> (Eschscholtz, 1821) were characterized by Scanning Electron Microscopy (SEM), Energy-Dispersive x-ray Spectroscopy (EDS), Atomic Force Microscopy (AFM), Fourier transform Infrared spectroscopy (FT-IR), UV-Vis spectrophometer and NIRQuest spectrometer. SEM images showed that the two sections of wings have different structures. The black with ‘red spot’ hindwings have ‘hair-like’ structures attached to the ridges and connected to the lamellae. On the contrary, the ‘plain black’ forewings have holes that separate the ridges. AFM analysis unveiled that the ‘plain black’ forewings have higher average surfaces roughness values as compared with the black with ‘red spot’ hindwing. EDS and FT-IR results confirmed the presence of naturally hydrophobic materials on the wings. The ‘plain black’ forewing exhibited strong absorptance (97%) throughout the solar spectrum range, which is attributed to the high melanin concentration as well as to the presence of holes in the scales. Biomimicking this wing could serves as equivalent solar absorber material. [ABSTRACT FROM AUTHOR]