These caddisflies were thick over the water in the evening on a cold, clear northwoods lake. They were in many places on the lake, all closer to the shady shore, which also was the shore most sheltered from the wind. I'm not sure which of those features attracted them.
Troutnut.com is a collection of pictures and information about fly fishing. Fly fishermen, fly tiers, and trout enthusiasts of all stripes can learn more about life beneath the surface of trout streams, as well as how to better imitate aquatic insects with artificial flies to catch trout. There are aquatic insect pictures, underwater pictures, landscape pictures, and a comprehensive reference to the common names of trout stream insects.