The extraordinary raspberry-like eyes of a tiny parasitic insect have been described for the first time. Strepsipteran insects, which live in the bodies of paper wasps, have a visual system not found in any other living creature. The bugs see out of structures that are made up of 50 self-contained eyes with retinas behind them. This is very different to other insects which use compound eyes composed of hundreds of facets that each take in a separate point of visual information, creating what amounts to a mosaic of pixels. The Cornell team looked specifically at the Xenos peckii parasite which lives a short and secretive life.
Females are sightless and never leave their wasp host.
Once mature, males must leave the host to find a mate and have just hours to complete the task before they die. Although chemical signals are released by the female to help the male find her, sight probably plays a crucial role as well. But the male presumably relies on his vision once he is close to the wasp. This composite lens arrangement allows the insect to have many more photoreceptors in a given area than would be possible with a compound eye. If you only have so much space on your head for eyes and you want to gather the most light, you want a composite lens eye.