Plant & Pest Diagnostics

Stoneflies (Order Plecoptera)

Stoneflies are aquatic insects and one of the few insect groups that emerge as adults in winter and early spring. The nymphs or immatures live on or about stones in streams and rivers, hence their common name. These insects do not feed on people, animals, plants or trees; they do not invade our pantries or nest in our homes. Their presence should be considered a good omen because they only occur in clean water. Adults are poor fliers and usually do not travel far from the stream or river they emerged but some may travel up to a half mile away. Stoneflies do not live long as adults, so their numbers should begin to decline in a week or two. Chemical control is not necessary or recommended.