Immature stoneflies live underwater (technically they’re called naiads), then crawl onto shore to go through their last molt and become a winged adult. The final molt leaves behind a beautiful and fascinating shell called the exuviae.
The naiad feeds on plants, decaying organic matter, and other insects. The nymphal stage lasts from one to four years. The adult stage lasts only for a few weeks, long enough to mate and lay eggs.
The adults are earth tones mostly some hue of brown or yellow. They have fairly long antennae, wings that fold back along their body, and two long cerci (tail-like appendages).
The presence of stoneflies in a river system is a sign of good water quality because they require clean, well-oxygenated water. A rocky aggregate bottom with high dissolved oxygen levels is often a productive area for stoneflies.
