Description
The Stonefly is a larger water insect with two pair of wings that it folds flat against its body when at rest. It has three pairs of legs with a claw on the ends, a pair of long, thin antennae and two tail-like appendages at the rear of its body.
The Stonefly lives most of its life underwater as a nymph, feeding on algae and other organic materials that fall underwater, remaining underwater for up to four years until they emerge as adults after full development. The adults swarm to mate and the male dies soon after mating. The female carries her eggs on her body then deposits them the water before dying.
The Stonefly is attracted to bright lights and the adults may become a nuisance when they swarm to lights at night.
Color
Brown to black
Size
up to 2”

Control Advice
Use to yellow ‘bug’ lights in outdoor lighting areas to discourage Caddisflies from swarming around lights at night. Use a vacuum to remove Stoneflies that come inside.
Active Seasons
The Stonefly is most active in spring and summer.