DF20. The Black Griffith's Gnat Dry Fly

THE GRIFFITH'S GNAT FLY PATTERN
Midges or gnats are the staple diet of most trout. These tiny insects are found on most rivers, lakes and streams. This popular American Fly is used to imitate egg-laying adult midges and emerging midges. George Griffith, one of the founding fathers of the American Trout Unlimited, created one of the most important midge dressings. The Griffith's Gnat is simple, no more than a peacock herl or dubbed body, overwound with grizzly hackle. The beauty of the fly is how it floats half in and half out of the surface film representing something stuck, trying to emerge from its shuck. After having had some coverage in the British and European fly fishing press it has now successfully crossed the Atlantic. These flies are very small having a black body and whitish wings. The small black midge (polypedilum nubeculosus) and similar species are common and widespread. Hatches are normally during the evening and often prolific. In the late summer you may come across early morning hatches if the temperature is right. The larvae and pupae of these insects can be found in countless numbers in stagnant and stillwater. You will find them in rainwater butts as well as the margins of lakes, ponds and ox-bow sections of rivers.  

DRY FLIES
The dry fly is designed to float on the surface of the water. To prevent it sinking, water repellent hackles are wound around the hook to distribute the weight over the surface of the water. The hackles also simulate the legs and splash of an aquatic or terrestrial insect trapped on the water surface. Most Dry flies are deceivers designed to imitate a specific natural fly like the crane fly, ant and hopper series of flies. Other flies like the Adams are more general designs that are just intended to produce an edible looking fly. Dry fly fishing has always been regarded as the supreme art in fly fishing circles. Accurate presentation of the fly can be essential. Trout will rise to a variety of natural flies but as far as the dry fly fisherman is concerned the mayfly hatch has to be the favored time. In almost all instances where trout feed on drowning insects the rule is not to move the fly. An imitation is far more likely to succeed if it is cast out and then left. So long as it is cast in the right spot.

The color of the fly is always important when matching the hatch, then size is the next important decision. The artificial fly does not have to be a precise imitation of the natural insect, but what is important is how and where it is presented in relation to the depth of water. This includes the height at which the fly floats above the surface of the water. Some fish will greedily take flies that are floating in the surface but ignore flies that are floating above it and visa versa depending on the conditions that day. Use your eyes to see which natural insects the fish are taking. A high-floating dry fly will have more chance of being taken on a bright day because of its visibility, but if it does not dent the surface film on a dull day it will be less effective. A fly floating in the surface on a sunless day leaves a much more visible halo of outlining light which surrounds it.

MAYFLIES
Some adult mayflies hatch throughout the year but other species hatch only during certain months of the year. The term Mayfly applies to all members of the order of insects not just those that emerge in May. There are hundreds of fly patterns tied to imitate the many different mayflies and stages of their development. The natural insect belongs to the group of insects called Ephemeroptera. Ephemeros means 'lasting a day' and peteron means 'a wing'. Mayflies have cylindrical bodies, slender legs and two pairs of veined wings which are held vertical when at rest. They are found all over the world and are commonly called up-winged flies in some areas. The adults do not feed and live for only a very short time: most less than a day and some only for a few minutes. 

The aquatic Mayfly nymphs moult anything from 12 to 50 times and take up to two years to reach adulthood. In any square yard or meter of a stream there may be a few hundred to many thousand mayfly nymphs. They are an important part of any predator fish's diet. The fully grown nymph swallows air and floats to the surface where it emerges into the subimaginal stage. The Dun sits on the water surface for a few seconds after hatching to enable the blood to pump up it's wings and for them to dry. The colder the weather the longer this takes. It is very vulnerable to attack at this time from under the water surface. On windy days, gusts can topple over the drifting duns and drown them. If you cannot see any rises for surface floating duns during a hatch on windy days the fish are feasting sub surface on the unlucky sinking drowned duns as well as the emerging nymphs. Try using a partridge and Yellow Soft hackled spider wet fly, Gold Ribbed Hares Ear Wet fly, Blue Dun or Light Cahill wet fly to imitate drowned duns, depending on the local insects body color that can range from pale yellow, olive to tan. Wing color also varies throughout the world from pale gray to pale yellow. I often fish these wet flies on a dropper about 18 inches behind a dry fly. The soft hackle or wet fly imitating the drowned dun often catches the fish when nothing else works.

If the drifting newly emerged duns have not been eaten by a fish during this vulnerable time, they fly off and hide on the surrounding vegetation. Within 24 hours the duns molt into spinners and and are ready to mate. Mating swarms are formed by the males to attract females. They also occur at dawn or dusk to reduce the chances of single insects being taken. When a female flies into the swarm she mates with a male. The males fall onto the water spent and drown. They are known as 'spent spinners'. The females return to the riverside vegetation for a short period whilst the eggs mature. When the eggs are ready the females fly out over the water, dip into the water, lay their eggs and then fall into the water spent.  Some females species swim down to attach their eggs to submerged vegetation or objects. Others just land on the water surface making tempting targets for hungry trout. Try and scoop up a natural spinner floating dead in the water surface and match the body color with a parachute dry fly like a Greenwells, Tup's Indispensable or Gold Ribbed Hares Ear Parachute.