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Isonychia Nymph
A nymph, tied #10–14, a summer pattern. It is tied against 1 named insect in this book — June–September.
- #10–14Hook size
- nymphType
- SummerSeason
- 1Hatch matched
What it looks like
A drawing, not a photograph, and not traced from one. Its proportions were read off 5 independent reference photographs of the pattern and written down as 5 measured characteristics — wing angle, tail length against the shank, how far a hackle fibre reaches — every one of which had to hold across more than one of them before it could be drawn. What survives across many photographs of a fly is the fly.
What it imitates
Each of these is the same hatch record the app's own panel reads, so a pattern recommended on a river card in the app is recommended for one of the insects below.
Tying recipe
In tying order. This dressing is the standard one — these patterns have been in the publicrecord for decades — and materials substitute freely: the proportions and the silhouette are the pattern, not the brand of dubbing.
| Hook | Nymph hook, sizes 10–14 |
|---|---|
| Thread | Dark brown 8/0 |
| Tail | Three dark pheasant fibres |
| Body | Dark brown-maroon dubbing |
| Dorsal stripe | A single white or cream fibre along the back |
| Legs | Dark partridge or hen |
| Weight | Lead-free wire under the thorax |
When to fish it
Swum, not drifted. The natural is a strong swimmer heading for the bank, so fish it across and let it rise at the end.
A summer pattern. The insects it matches are active june–september, in water from 55°F to 70°F.
Target species
- Trout
Rivers it fishes well
Rivers with a page here that sit in the regions where the insects this pattern imitates are recorded. It is a claim about coverage, not a report of a fish caught.
- Au Sable River northern lower Michigan · July mean 72.1°F
- Catawba River the North Carolina mountains · July mean 76.7°F
- Jackson River the Virginia mountains · July mean 66.3°F
- Muskegon River northern lower Michigan · July mean 71.0°F
- Escanaba River the Upper Peninsula · July mean 68.3°F
- Saint Croix River northern Wisconsin · July mean 77.2°F
- Smith River the Virginia mountains · July mean 51.9°F
- Tygart Valley River the Virginia mountains · July mean 74.6°F
- Kalamazoo River southern lower Michigan · July mean 71.3°F
- Aaron Creek the North Carolina mountains · July mean 76.7°F
- Aaron Run the Virginia mountains · July mean 77.1°F
- Aarons Run the Virginia mountains · July mean 74.2°F
Related patterns
Same type of fly, or tied for the same insects.
- Prince Nymph nymph · #10–18 — An attractor nymph with biot wings. Nobody agrees what it imitates and it does not matter.
- Zug Bug nymph · #12–16 — Peacock and a dark body. Older than most of us and still catching fish.
- Black Stonefly Nymph nymph · #12–18 — Dead-drifted along the bottom. Stonefly nymphs are always present in rocky water.
- Copper John nymph · #12–20 — Heavy enough to be the anchor fly. Gets the whole rig down in one cast.
- Cranefly Larva nymph · #6–10 — A fat pale grub. Best in the day or two after high water.