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Sowbug

A nymph, tied #14–18, carried year round. It is tied against 2 named insects in this book — all year.

Flat, grey and unglamorous, this is a nymph tied to sit low and wide the way a crustacean does, and in limestone water that crustacean is the main food item there is. It goes on a scud hook in sizes 14 through 18, grey 8/0 thread, with a body of grey-brown dubbing kept flat and picked out at the sides, a shellback of grey Scud Back or a turkey quill strip, a fine wire rib over it and a few turns of lead underneath. It is tied against the sowbug, Asellus spp., and the scud, Gammarus spp., both of them crustaceans available all year in water anywhere from 33 to 70 degrees, which is why the fly is carried in every season. It is fished on the bottom, in limestone water and tailwaters, all year round for trout — slower and flatter than a scud, and fished the same way.

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.

A cress bug — flat, grey, and everywhere on a limestone stream. It does not swim, so it is fished dead on the bottom and the pattern is deliberately drab. Drawn at #16 — 7.0 mm of shank and 3.5 mm of gape on a Tiemco 100.
#14#16#185 mm
The bare hook at every size this pattern is tied in, all to the same scale. There is no industry standard behind a hook number, so these are Tiemco 100 measurements and another maker's 14 will differ a little.

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.

HookScud hook, sizes 14–18
ThreadGrey 8/0
BodyGrey-brown dubbing, flat and picked out at the sides
ShellbackGrey Scud Back or a turkey quill strip
RibFine wire
WeightA few turns of lead

When to fish it

Limestone water and tailwaters, on the bottom, all year. Slower and flatter than a scud, and fished the same way.

Carried all year. The insects it matches are active all year, in water from 33°F to 70°F.

Target species

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.

Related patterns

Same type of fly, or tied for the same insects.

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