The natural world is full of colour, and few groups of animals are as colourful as insects. From the dramatic black and yellow stripes of wasps and striking spots of ladybirds to the dazzling metallic sheen of jewel beetles, insects show a kaleidoscopic array of hues, patterns and optical effects.
But exactly why insects are so colourful isn’t always clear. How and when did insects evolve colours, and have their roles always been the same? We recently discovered some spectacularly preserved blue-green colours in the scales of 13,000-year-old fossilised weevil beetles. Our find, published in Biology Letters, sheds light on the evolution of the most complex colour-producing structures known in insects: 3D biophotonic crystals.
Until now, we had only ever found one example of such preserved crystals in a fossil. Our new specimen supports the idea that 3D colour-producing structures may have evolved as a means of camouflage rather than to attract attention. But more importantly, the discovery indicates that these fossils may be much more common than we previously thought. This opens up greater potential for us to learn far more about the evolution of these “structural colours”, and the biophotonic crystals that produce them. MORE