Fly tiers have devised many artificial flies to simulate cased and free-living larvae. On flowing water, cast a larva imitation up-current of fish and allow it to dead drift near the bottom, simulating a live larva caught in the flow. A caddisfly Six months to a year after it is born, a caddis larva matures to become a pupa. As it matures, an adult body forms inside the pupa. Then the adult cuts its way out of its pupal skin, or chamber.
Some species climb out of the water as they emerge, and others swim to shore.
Adults The most exciting fishing, however, occurs when caddisflies emerge on the surface. The emerging adult generates gasses that float it to the surface. As it rises, its pupal shell expands and bursts, and the adult pops out of the water. Some species emerge with such speed that fish leap out of the water after them. Other species have to pause for a moment before taking off.