Iridescence is a form of structural colour which uses regular repeating nanostructures to reflect light at slightly different angles, causing a colour-change effect.
It is common in nature, from the dazzling blues of peacock’s feathers to the gem-like appearance of insects.
Though it may seem counterintuitive, these bright flashy colours may serve as camouflage, according to recent research showing that intense iridescence obstructs a bumblebee’s ability to identify shape. If it confuses bumblebees, it is also likely to confuse other insects with similar visual systems such as wasps and hornets.
When presented with different types of artificial flower targets rewarded with sugar water, the bees learned to recognise which shapes contained the sweet reward. However, they found it much more difficult to discriminate between flower shape when the targets were iridescent.
The research is described in a paper in Scientific Reports.