isonychia (bicolor) Ephemeroptera(Mayfly) Family: siphlonuridae Genus: isonychia Species: bicolor Common Name: Dun Variant, Leadwing Coachman Important isonychia Statistics Size: 13-16 mm Water Temp: less than 70 degrees Hook: #10 2x Emerging: Evening best. earlier when temperatures are cooler Hatch Date: June and sporadically to Sept Habitat: Fast moving boulder strewn streams seem to be the favorite habitat although slower streams have good populations SPECIES LIFE STAGE HOOK BODY COLOR WING COLOR TAIL COLOR isonychia dun #10-12 dark gray medium texture dark ginger isonychia spinner #10-12 dark reddish brown brown antron brown mink isonychia emerger #10 Isonychia Comments: Nymph Nymphs move to calmer shallow water to hatch by crawling out of the water onto rocks. The trout key on this activity and nymph fishing is very productive using a Zug Bug. Try casting upstream and retrieve by pulling downstream a little faster than the current. Dun Trout attack the duns that fall or are blown into the water often practically climbing a rock to get them. Drift the fly on the current edges and in the pocket water behind rocks.Try to imitate the actions of the duns. Spinner The late season spinner falls occur just before dark and provide frantic action for about 30 minutes. The full spent pattern works best. Find a good location to cover several feeding stations and be prepared for fast action. Mayfly |Entomology |Trout |flyfishing copyright©2000flyfisherusa