A female Closterocerus coffeellae, a wasp collected in Colombia, looks drab against a white background and shines against black. Researchers at Lund Universityin Sweden have discovered that the insect species hymenoptera wasps and diptera flies theyve been studying for decades reflect light off their wings in rainbow like patterns. The effect is a bit like oil on water, but these patterns are permanent, suggesting they may play a role in insect communication. The wings of the flies and wasps are transparent, but they reflect about 20 percent of the light that hits them, the researchers found. Its this light that creates the shining patterns, just like a thin film of soap or oil on water creates a rainbow colored glare.