title: Variable multilayer reflection together with long-pass filtering pigment determines the wing coloration of papilionid butterflies of the nireus group.
abstract: The dorsal wing surfaces of papilionid butterflies of the nireus group are marked by bands of brilliant blue-green-colored cover scales. The thin, cuticular lower lamina of the scales acts as a blue reflector. The thick upper lamina forms a dense two-dimensional cuticular lattice of air cavities with a pigment acting as a long-pass optical filter. Reflectance spectra of small scale areas oscillate, but for large scale areas and the intact wing they are smooth. Theoretical modeling shows that the oscillations vanish for a scale ensemble with varying layer thicknesses and cavity dimensions. The scales combine in a subtle way structural and pigmentary coloration for an optical effect.
authors.affiliation: School of Physics, Exeter University, Exeter EX4 4QL, UK. t.m.trzeciak@gmail.com
authors.forename: Tomasz M
authors.initials: TM
authors.lastname: Trzeciak
authors.forename: Bodo D
authors.initials: BD
authors.lastname: Wilts
authors.forename: Doekele G
authors.initials: DG
authors.lastname: Stavenga
authors.forename: Peter
authors.initials: P
authors.lastname: Vukusic
mesh_terms: D000818:Animals; D002080:Butterflies / Q000033:anatomy & histology* / Q000145:classification; D003116:Color; D008027:Light; D055620:Optical Phenomena; D010858:Pigmentation; D012542:Scattering, Radiation; D013053:Spectrophotometry; D014921:Wings, Animal / Q000033:anatomy & histology