Insects wing look quite ordinary. Transparent, with the occasional brownish spot on them. But a researcher from Lund University put them on a black background and all of a sudden an explosion of colours reveals a kaleidoscope of patterns that includes greens, blues, violets, oranges - but not red.

It was a French biologist back in 1843 to notice the rainbow of colours of insects' wings but he never mentioned their pattern. And it is precisely the pattern that identifies the different species, like a sort of unique fingerprint.

The view is incredibly b