Thermonectus marmoratus

Description

Thermonectus marmoratus is a relatively colorful North American species of diving beetle known by the common names sunburst diving beetle and spotted diving beetle. The beetle has recently become notable when it was discovered that its aquatic larval stage has been found to have used in its principal eyes two retinas and two distinct focal planes that are substantially separated, in the manner of bifocals to switch their vision from up-close to distance, for easy and efficient capture of their prey, mostly mosquito larvae. This is the first ever recorded use of bifocal technology in the animal world. Because of their bright colors, they are often displayed in zoos, sometimes together with Abedus herbert (also found together in the wild) and other aquatic beetles.