We measured the visible reflectance spectra of whole wing sections from three species of iridescent butterflies and moths, for normal incidence, integrated over all reflected angles. In this manner, we separated the optics of the thin films causing the iridescence from the optics of the rest of the scale. We found that iridescence reduces solar absorption by the wing in all cases, typically by approximately 20% or less, in contrast to claims by Miaoulis and Heilman [Ann. Entomol. Soc. Am. <b>91,</b> 122 (1998)] that the thin-film structures that produce iridescence act as solar collectors.
© 2000 Optical Society of America
(170.1420) Medical optics and biotechnology : Biology
(240.0310) Optics at surfaces : Thin films
(260.3160) Physical optics : Interference
(310.6860) Thin films : Thin films, optical properties
Daniel W. Koon and Andrew B. Crawford, "Insect Thin Films as Sun Blocks, Not Solar Collectors," Appl. Opt. 39, 2496-2498 (2000)