ABSTRACT
S toneflies, as an order, form a group with rather obscure habits. They are likely to be overlooked by the general collector. As many as a third of the
species emerge, mate, feed, and die during the winter months when most collectors are indoors. It can prove a challenge, however, to tramp through the snow in search of those species and to track down the habitats of the other species that become adults during the summer months as well. Because of their dependence upon flowing fresh water during their immature life, some members of the order are threatened by the pollution of our streams, although they exhibit considerable variation in their sensitivity to pollutants.
