Look for net-spinning caddis hiding in shelters attached to submerged rocks in riffles and runs. Flowing water keeps the nets open; when removed from the water they collapse. So when a rock is lifted from the water, the shelter is visible, but often not the net.
Spotted sedge adults found on streamside foilage during the early hours of the day indicate that an evening emergence has taken place. Pick a few submerged rocks and check for shelters built from sand and plant debris. Look for a closed shelter and carefully open it; remove pupa and match your imitation to its size and color.
If theses Caddisflies have been hatching, you will notice the adults on or flying about streamside foilage near riffles and runs. Enough adults end up in the water during the day to keep trout interested so fishing a dry-fly imitation upstream along bushy banks is worth the effort.