Olive Crystal Stonefly flyfishing Nymph for stream and river trout fishing. If the water is not clear following a rain storm and you cannot see your target fish you will have to read the water to try and find out the best place to cast your fly.
STONEFLY NYMPH FLY PATTERNS. Hook size 10 - $US each
OLIVE CRYSTAL STONEFLY NYMPHS
Larval (nymph) development of a stonefly may take from three months to three years. The time taken depends on species and climatic conditions. Stonefly nymphs in food rich warmer environments develop faster that those aquatic insects in colder locations. Some stonefly larvae can have as many as twenty two moults, shedding of their exoskeleton before adulthood. This is called instar. Unlike mayflies and caddis that hatch on or in the water surface film, Stonefly nymphs crawl out of the water onto river and lake banks, overhanging vegetation or boulders to emerge into the winged form of the stonefly.
Mating takes place on shore. The female stonefly adults return to the water to lay their eggs. Some will hover over the water and dip in it to deposit their precious load of eggs whist some series females crawl back into the water. I have noticed that female stoneflies from early season hatches tend to lay their eggs during the day. Later season hatches, when day time temperatures can be very warm, lead to evening egg laying activity which can extend after dark. Stimulator stonefly patterns work well at this time of the year.
Unlike the plentiful falls of spent mayfly spinners that are a welcome food source for hungry trout, spent stonefly adults are infrequent and do not form a major part of a fish’s diet. The exception is some of the smaller species who have a heavier hatch. When the individual exhausted adult stonefly falls to the water surface it may enter the drift and become trapped with others in eddies and backwater foam. You may find small collections of them drifting down river and lake banks having been blown their by the prevailing wind. A large Shipman’s buzzer fished on the surface can bring results if drifted along near the river bank. So can a size 10 black or olive woolly bugger fished just under the surface.
Stoneflies like unpolluted well oxygenated water. You will find them in most flowing streams and rivers of North America. There are relatively few species in Europe. Lakes are not a stonefly’s prime habitat but you may find them near feeder rivers and streams where fresh oxygen rich water flows freely. If there is a regular prevailing wind you will find them near wave washed stony shallows. Another location to explore are lake outlets where the water tumbles over weirs and boulders. I often tie on a stonefly nymph under a strike indicator or dry fly and float it past the inlet and then let it drift back out into the lake before I retrieve it.
Stonefly nymphs forage for food amongst the vegetation, gravel and debris found on the bottom. They often stumble onto a section of faster flowing wager and get carried away. This is when they become fish food. Trout and Salmon wait in slower calmer water behind boulders or position themselves in a crease, where faster water meets slower moving water, to watch out for passing food. When they see a helpless Stonefly nymph drift by they grab it.