The tropical Paris Peacock (Papilio paris) butterfly – not to be confused with the temperate or European Peacock ( (Inachis io) – is widely distributed throughout India and South East Asia. I came across this species on the slopes of Doi Chiang Dao, on the road to the Den Ya Kat substation (a popular spot for birdwatching). The butterflies were mud-puddling on the banks of a small stream some way down the mountain. Despite being so large and colourful, I did not manage to get a shot that I was really pleased with, but I did manage to capture the fore- and hind-wings in profile.
I cropped this image some more, to show in detail the small green scales which give the butterfly its overall green colouration. These very bright, light reflecting scales are set on the dark background of the wings, and it will be seen, are more densely clustered on the hind wings and towards the outer margins of the forewings. The iridescence of the butterfly scales is produced by microscopic ridges and facets on the surface of the scale. The mechanism for these so-called structural colours is thought to be coherent scattering of light by the nanostructures on the scale itself (1).
The type specimen – the individual which first received this scientific name, and which can be used for comparisons – is in the Natural History Museum in London, and was named by the great Swedish naturalist Carl Linnaeus in 1758 (2).
1) Richard O. Prum, Tim Quinn and Rodolfo H. Torres (2006). Anatomically diverse butterfly scales all produce structural colours by coherent scattering. The Journal of Experimental Biology 209, 748-765. http://jeb.biologists.org/content/209/4/748.long