Snatcher fishing flies were developed as an imitation of the large buzzer pupae on Scottish Lochs, however itis such a versatile fly it really is super when the trout are in the upper levels of the waters, emergers are of course the insect emerging. We have here the selection from Trout and Salmon Magazine. An Emerger fly is designed to resemble the not quite mature hatching aquatic insect as it leaving the water to become an adult insect. Emerger flies are generally considered freshwater trout flies.