The beadhead nymph is designed to imitate the small subsurface and emerging insects in rivers and lakes. Midges and emergers usually represent an early stage of life for flies that lay eggs in the water. Often very tiny in size, Drift this midge larva pattern through tail-waters or still-water,It seems rainbow trout are particularly fond of this red nymph, all trout species will find this thing irresistible.Midges are active year-round , Folks say it is luck to carry a few of these.