Whirligig Beetles Active
Congratulations to Stein Feick, the first person to correctly identify the Mystery Photo as a Whirligig Beetle! You usually see this aquatic beetle swimming around and around in circles on the surface of a pond searching for prey. A unique feature of most beetles in this genus is their divided eyes. Each eye is completely separated into two portions (see photo). One portion (dorsal) is above the water line and the other (ventral) is beneath the water on each side of their head, allowing them to see both in the air/on the surface of the water as well as under the water. The dorsal eyes have a limited field of view, so these beetles rest one of their antennae on the surface of the water to help them detect any motion caused by prey.
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