Crayfish (Orconectes spp.)

Crustacean, hatching May–October, active in water between 55 and 78°F, and imitated at #4–8. Recorded from northern lower Michigan, southern lower Michigan and the Upper Peninsula, where 1140 Michigan rivers on this site carry a page.

Not an insect at all but a freshwater crustacean, olive to rust to almost blue, running backwards in short bursts along the bottom. Where they are abundant they are the largest single item in a big brown trout's diet, and the largest single meal in most trout streams. Imitations are tied on size 4 to 8 hooks. The active band runs 55 to 78 degrees, wide enough to cover cold, cold-transitional, cool and warm water, and the peak stretches from May through October. Presentation is the whole discipline: fished on the bottom, moved in short strips or hops, and allowed to fall between them. A crayfish that swims steadily upstream is imitating nothing that has ever lived. A Clouser Crayfish in 4 to 8 is the literal match; a brown Woolly Bugger in 2 to 12, a Zonker in 2 to 8, or a Circus Peanut in 2 to 6 all cover the same profile.

#4–8Hook size
55–78°FWater, active
May–OctPeak months
1Life stage fished

Subbasins with trout water where it is on record: 42 of Michigan's 59.

See Michigan's trout water on the live map → Every reach coloured by water temperature — the water these hatches come off.

What it is

Crustacean · Orconectes spp. · adult

Not an insect. A freshwater crustacean, olive to rust to almost blue, running backwards in short bursts along the bottom. Where they are abundant they are the largest single item in a big brown trout's diet.

The largest single meal in most trout streams. Fished on the bottom, moved in short hops, not stripped.

When it hatches

Peak is May–October. The pale months either side are the shoulder — the app widens a peak by one month in each direction and recommends the bug there, and no further: that widening is bounded so that a bug peaking in May is never offered in August.

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peak shoulder not recommended

Water conditions

The band is a water temperature, not an air temperature, and it is the range in which this insect is worth fishing — for a mayfly that is the emergence window; for a scud or a midge it is simply the range trout will still eat one in.

55°F 78°F

Active from 55°F to 78°F. On this map that is cold, cold-transitional, cool, warm water — the band crosses 3 of the three breaks the river colours use. Breaks at 58, 64 and 70°F.

Stages

What the insect is doing, and what that means for what you tie on.

Stage	What it is
adult	Fished on the bottom, moved in short strips, and allowed to fall. A crayfish that swims steadily upstream is imitating nothing that has ever lived.

Matching flies

4 patterns in this book imitate the Crayfish, across its stages. Which one to tie on follows the stage the water temperature says it is in — the app makes that call on a live reading; this page lists the whole set.

Where to find it right now

The rivers with a page here that sit in this insect's regions, with a USGS gauge reporting water temperature. This list is re-ranked against the reading each gauge is sending now and today's date, so it is live — the fallback below it, if the readings do not arrive, is each river's measured July mean.

Regional presence

Regions, not collection records. This insect is recorded from the coarse regions below; nobody has surveyed which named river it has been caught on, and this page will not pretend otherwise.

northern lower Michigan MI
southern lower Michigan MI
the Upper Peninsula MI
the Wisconsin driftless WI
northern Wisconsin WI
the Virginia mountains VA
the North Carolina mountains NC

Rivers in these regions with a page here

Related hatches

Same family, or overlapping this one's calendar on the same water.

Open the trout map →Every trout stream near you, coloured by today's water temperature.