Stoneflies- Join the Search

Date: Saturday, January 25, 2025 from 10 a.m.-4 p.m.

Volunteers needed to survey for Stoneflies throughout the Rouge River!

It’s easy, fun, and a great way to learn about aquatic insects and the health of the river while contributing to science.

Pre-Registration is Required: 

Meet at the Plymouth Cultural Center (525 S. Farmer, Plymouth, MI 48170), then head out to the sites.

Thank you to Mercedes-Benz Financial Services for making the 2025 Stonefly Search possible!

Five Types of Stoneflies have Been Found in the Rouge River (map)

Stoneflies are a primitive group of insects named for their habitat of crawling on stones in a river. Most stoneflies have high oxygen needs, restricting them to clean well-oxygenated streams. Because of this, they are good indicators of stream quality. Some stoneflies hatch in winter which is why Friends of the Rouge volunteers look for them in January (info on events). If you are interested in joining the event, check out our recorded “Stonefly Refresher” to learn more about how and why we look for them

Stoneflies resemble mayflies but have longer antennae and two (rather than three) tails. Five types of stoneflies have been found in the Rouge River through the Benthic Macroinvertebrate Monitoring Program.

Slender Winter Stonefly (Capnid)

Slender winter stoneflies (Capnidae) – 38 sites – map
Perlodid stoneflies (Perlodidae) – 20 sites – map
Broad-backed stoneflies (Taeniopteryx) – 6 sites – map
Broad-backed stoneflies (Nemouridae) – 5 sites – map
Perlid stoneflies (Perlididae) -5 sites –  map

Stonefly Findings

• Check out what scientists found by examining Friends of the Rouge’s Stonefly Data in 2020
• First Stonefly Found in the Rouge in 2002
• Listen to WDET’s Craig Fahle interview Sally Petrella & Noel Mullett about the stonefly found in the Main branch of the Rouge River