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Giant water bugs just a curiosity

Jeffrey Hahn, Extension Entomologist

This giant water bug was found on the side of a building near a street light.
Photo:  Jeff Hahn, University of Minnesota Extension
Some people are finding a large, up to 2 1/3 inches long, insect outdoors around their homes or their work. Sometimes people think this insect is a beetle, a cockroach, or even an invasive species. In fact, it is the giant water bug, Lethocerus americanus.

This giant water bug is a common native species. It is olive brown with large front legs for grasping and holding prey and large, flattened back legs for swimming.

Where to find the giant water bug

 This insect is normally found in ponds and shallow edges of lakes where it uses it stout needle-like mouthparts to feed on insects, tadpoles, small fish, and other small aquatic creatures.

Although aquatic, giant water bugs can also fly. They will occasionally leave the water and fly off in search of mates or new homes. They are often attracted to lights so it is common to find them in yards, parking lots, ball fields, and other places with outdoor lighting.

Will it bite me?

Although this insect is not aggressive towards people, it is capable of administering a painful bite if mishandled. In fact, this giant water bug is sometimes called ‘toe biter’ because of its ability to bite.

However, with the proper precautions, this insect do not pose any problem to people. If you find a giant water bug, just ignore it and let it go its own way.  It's only a curiosity.
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