They are often large easy meals for trout. Stoneflies usually aren't known for being fished in the emerger stage, because they crawl out of the water to hatch. They can be fished in this stage especially at night with a large wet fly. Fishing these wets behind boulders and in seams where struggling emerging nymphs fall off of rocks or drift into awaiting trout can be very rewarding. Adult stoneflies can also be extraordinary fishing either late evening, nighttime, or early mornings.
Midges are important especially to smaller streams with less mayfly activity.
They can present some of the best fishing when other bugs are not around. Fine tippets and long leaders are usually a must to fish these tiny flies. Terrestrials are also an important food supply for trout. On smaller streams summertime terrestrial dry fly fishing can be great especially under overhanging trees. Ants, beetles, crickets, and inch worms are some of the important terrestrials to have in your box.