Grazing-incidence iridescence from a butterfly wing.
The Troides magellanus butterfly exhibits a specialized iridescence that is visible only when its hind wings are both illuminated and viewed at near-grazing incidence. The effect is due to the presence of a constrained bigrating structure in its wing scales that has been previously observed in only one other species of butterfly (Ancyluris meliboeus). However, whereas the Ancyluris presents wide-angle flickering iridescence, the Troides butterfly uses pigmentary coloration at all but a narrow tailored range of angles, producing a characteristic effect.
Lawrence
Chris
C
Defence Evaluation and Research Agency, Farnborough, Hants, United Kingdom. crlawrence@qinetiq.com
Vukusic
Peter
P
Sambles
Roy
R
D000818:Animals; D003116:Color; D007915:Lepidoptera / Q000033:anatomy & histology / Q000502:physiology*; D008027:Light; D008855:Microscopy, Electron, Scanning; D014921:Wings, Animal / Q000502:physiology* / Q000648:ultrastructure