Though less prolific than mayflies and caddisflies, many stonefly species make up for in size what they lack in numbers. Because they emerge by crawling out of the water on land, the hatching adults are not eaten for trout, but their large nymphs are welcome food year-round. In the Western states, where stoneflies are most prolific, trout sometimes feed selectively on the egg-laying adults as they return to the water.
This common name refers to only one order.
These are pretty much always called Stoneflies.
Stoneflies are the largest
of the three main types of trout stream insects. While far less important than caddis and mayflies in the East and Midwest where they are mostly thought of as handy nymphs to imitate when nothing much is hatching, it's in the West where this order comes into its own. They can cause outstanding fishing, and on many rivers their hatches are the premier events of the season.
The year begins with the little dark stoneflies of the Capniidae
, and Nemouridae
families as some of the only active aquatic insects available to trout. As the year progresses into late Winter and early Spring, the Large Springflies of the Perlodidae
family in the West and Willowflies of the Taeniopterygidae
are sometimes the first dry-fly insects of the season. When Spring fully arrives, so do the most significant stoneflies for the angler - the gigantic Pteronarcyidae
Salmonflies of western legend. The large Golden Stones of the Perlidae
supplement these hatches and are more common across the country. Summer brings on significant hatches of the Little Yellow Stones of the Perlodidae
family and the little yellow or green Chloroperlidae
flies that are common sights.