TY - JOUR
T1 - Structural ultraviolet ornamentation in the butterfly Hypolimnas bolina L. (Nymphalidae)
T2 - Visual, morphological and ecological properties
AU - Kemp, Darrell J.
AU - Macedonia, Joseph M.
PY - 2006
Y1 - 2006
N2 - Many butterflies exhibit structurally coloured wing patches that are stunningly bright and iridescent in their appearance, yet functionally obscure. These colours are often exaggerated in males, which suggests a sexually selected origin. We studied the visual properties, morphological basis, and interindividual variation of structural wing colouration in the common eggfly, Hypolimnas bolina L. (Nymphalidae). Males of this territorial species possess highly directional UV/violet colouration that fully overlaps smaller white patches on their dorsal wing surfaces. We sampled 56 males, including territorial residents and non-resident 'floaters' and assessed the properties of their structural colour using reflectance spectrometry and scanning electron microscopy. The patches reflect strongly in the UV range (300-400 nm), with a peak of ∼360 nm, and the wing scales in these regions exhibit a ridge-lamellar surface architecture that has known function in other species as a multiple thin-film interference mirror. Peak UV brightness was variable, and both brightness and peak hue varied systematically across age classes. UV brightness was also related to hue independently of the age-related variation. Territorial residents possessed duller UV markings than their non-resident contemporaries, which is not consistent with exaggeration due to male-male competition. The high phenotypic variance is, however, consistent with a putative role for this male-limited trait as a sexual ornament.
AB - Many butterflies exhibit structurally coloured wing patches that are stunningly bright and iridescent in their appearance, yet functionally obscure. These colours are often exaggerated in males, which suggests a sexually selected origin. We studied the visual properties, morphological basis, and interindividual variation of structural wing colouration in the common eggfly, Hypolimnas bolina L. (Nymphalidae). Males of this territorial species possess highly directional UV/violet colouration that fully overlaps smaller white patches on their dorsal wing surfaces. We sampled 56 males, including territorial residents and non-resident 'floaters' and assessed the properties of their structural colour using reflectance spectrometry and scanning electron microscopy. The patches reflect strongly in the UV range (300-400 nm), with a peak of ∼360 nm, and the wing scales in these regions exhibit a ridge-lamellar surface architecture that has known function in other species as a multiple thin-film interference mirror. Peak UV brightness was variable, and both brightness and peak hue varied systematically across age classes. UV brightness was also related to hue independently of the age-related variation. Territorial residents possessed duller UV markings than their non-resident contemporaries, which is not consistent with exaggeration due to male-male competition. The high phenotypic variance is, however, consistent with a putative role for this male-limited trait as a sexual ornament.
UR - http://www.scopus.com/inward/record.url?scp=33747101642&partnerID=8YFLogxK
U2 - 10.1071/ZO06005
DO - 10.1071/ZO06005
M3 - Article
VL - 54
SP - 235
EP - 244
JO - Australian Journal of Zoology
JF - Australian Journal of Zoology
SN - 0004-959X
IS - 4
ER -