Brown stone fly nymphs are easily distinguishable from mayfly nymphs in that they are tubular in shape and have 2 large wing pads , they vary in size from 10mm -25mm.Their colour varies from olive-brown through to a chocolate -chestnut and they are found among more bouldery well oxygenated stretches of river.It always pays on arrival to the river to roll over a couple of stones/boulders on the waters edge to see what aquatic life is around and then based on what is seen tie on an appropriate size/coloured nymph.
I have had great success with brown stone fly patterns the past couple of seasons in our more boisterous back country rivers and streams and carry them in sizes 8-14 some heavily weighted with Tungsten beads and lead to get down in deeper faster water and others no weight at all.
One particular day this past season a client had drifted half a dozen nymphs of varying size and weight past a large fish that was swaying in the current , the fish showed little or no interest in his offerings ,so the decision was made to try one more pattern before moving on upstream to find the next feeding fish ,on went a size #8 brown stone fly pattern and boom ! the fish took first cast.
Miki with a good fish taken on a size 8 Brown stone fly nymph,whilst removing the hook we noticed quite a few naturals still in it's mouth.A great fly to carry in the fly box especially for the visiting angler.
Feel free to contact me with any questions you may and to start plan your fly fishing New Zealand adventure now !