Trout eat Red Mormon Crickets when they jump into rivers. These red hoppers were made famous by nearly destroying the crops of the early Mormon settlers in Utah in 1848. They eat everything in their path.
GRASS HOPPER AND CRICKET FLY PATTERNS. Hook size 12 - $US each
Red Mormon Crickets are not most intelligent of creatures as they will walk right into the river as well as hopping into it to their death. The trout love them. Being up to 2 inches long they make quite a big meal. They are found in Western North America.
Most of the dry fly patterns in your fly box imitate aquatic insects like mayflies and caddis. You may want to restock them with some terrestrials. Studies have shown that on some waters, during certain parts of the season, trout actually eat more grasshoppers, crickets, termites, beetles and ants. This is especially true if the river or lake you fishing is surrounded by farmer’s fields.
Grasshoppers are large insects that do not look before they leap. I have watched many commit suicide by just jumping from the river bank onto the water surface. Some are blown on to the water but most just jump onto it of their own free will. They should realize they cannot swim. The do not drown immediately. They float on the surface film and struggle, trying to get out of the liquid hell they have ended up in. It is this disturbance that attracts the attention of nearby hungry trout. A grasshopper represents a substantial meal to trout. This food source is a lot bigger than a nymph or emerging dun and therefor very tempting.
The one thing that will scare away a fish is that if its grasshopper prey suddenly develops super powers and starts swimming against the current. The trout are programmed to expect this type of surface food to drift helplessly on the surface with the water flow and not fight it. Let your imitation grasshopper dry fly pattern to drift drag free on the surface over where you believe there are lurking trout. As you get near give you hopper fly a small tweak to imitate a real grasshopper trying to struggle against being drowned. Keep your eye on your fly and wait for the take.