Some insects remain active during the winter, and among them are the winter stoneflies (Plecoptera: Taeniopterygidae). Young nymphs spend the season in cold, fast moving rivers and large streams feeding on plant material and organic detritus. By late winter or early spring they’ve grown large enough to leave the water and molt into adults.
This week I started noticing quite a few adults of one species near my house in southeast Michigan. Considering their numbers, it would appear the nearby River Raisin is a great nursery for the nymphs.
Adult stoneflies live just long enough to mate and lay their eggs in the rivers where they grew up. After the next generation of nymphs hatches, they enter dormancy until late in the year. Once winter arrives, they begin the cycle all over again.