Colors and pterin pigmentation of pierid butterfly wings

Abstract

The reflectance of pierid butterfly wings is principally determined by the incoherent scattering of incident light and the absorption by pterin pigments in the scale structures. Coherent scattering causing iridescence is frequently encountered in the dorsal wings or wing tips of male pierids. We investigated the effect of the pterins on wing reflectance by local extraction of the pigments with aqueous ammonia and simultaneous spectrophotometric measurements. The ultraviolet-absorbing leucopterin was extracted prominently from the white Pieris species, and the violet-absorbing xanthopterin and blue-absorbing erythropterin were mainly derived from the yellow-and orangecolored Coliadinae, but they were also extracted from the dorsal wing tips of many male Pierinae. Absorption spectra deduced from wing reflectance spectra distinctly diverge from the absorption spectra of the extracted pigments, which indicate that when embedded in wing scales the pterins differ from those in solution. The evolution of pierid wing coloration is discussed. r

Quantifying the refractive index dispersion of a pigmented biological tissue using Jamin–Lebedeff interference microscopy

“…Pigmentary coloration is common in many animals; for instance, blue-absorbing carotenoids produce the yellow color of the feathers of many songbirds, 1,2 and the ultraviolet-and blue-absorbing pterins in pierid butterfly wing scales produce white (Small White, Pieris rapae) and yellow (Eastern Pale Clouded Yellow, Colias erate) wings, respectively. 3 Due to their usually high concentration, the pigments act as effective highpass spectral filters. However, because absorption is intimately linked to the refractive index, a strongly absorbing pigment can increase the refractive index and can thus strongly influence the coloration.…”

Papiliochrome II pigment reduces the angle dependency of structural wing colouration innireusgroup papilionids

“…The spectral sensitivity of butterflies extends into the UV, and therefore the Whites (Pieridae) see each other as brightly coloured. The absorption of other pterins common in pierid butterflies, xanthopterin and erythropterin, extends into the blue and green wavelength ranges, respectively, and thus the wings have a yellow, orange or red colour (Morehouse et al, 2007;Wijnen et al, 2007). Similarly, several Heliconius species have yellow scales owing to the violet-absorbing pigment 3-hydroxykynurenine (3-OHK) (Gilbert et al, 1988;Reed et al, 2008;Briscoe et al, 2010), which is the precursor of the ommochromes xanthommatin and dihydroxanthommatin that, in turn, cause orange-and red-coloured scales (Reed et al, 2008).…”

“…In Morpho butterflies, melanin pigment below the multilayered ridges enhances the saturation of the colour signal, because transmitted light which potentially can be scattered back by the wing or other scale structures is effectively absorbed (Mason, 1926;Kinoshita and Yoshioka, 2006). In pierid butterflies, the interference reflectors act in the wavelength range where the wing pigments strongly absorb and thus create a chromatic colour signal, which increases contrast and/or visibility (Morehouse et al, 2007;Wijnen et al, 2007;Wilts et al, 2011;Pirih et al, 2011).…”

Theoretical Study on the Relative Energies of Neutral Pterin Tautomers

“…Pterins participate in relevant biological functions behaving as inhibitors (1), enzymes (2)(3)(4), coenzymes (5,6), sensitizers (7)(8)(9), and pigments (10). In the past decade, the photophysical and photochemical properties of pterins have been systematically studied (11).…”