Yellow Drake (Ephemera varia)

Mayfly, hatching June–August, active in water between 58 and 70°F, and imitated at #10–12. Recorded from 5 of the 8 regions this map covers, across Michigan, Wisconsin, Virginia and North Carolina.

#10–12Hook size
58–70°FWater, active
Jun–AugPeak months
4Life stages fished

Subbasins with trout water where it is on record: 75 of 326 across the 6 states this map draws.

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

What it is

Mayfly · Ephemera varia · nymph → emerger → dun → spinner

A large pale yellow mayfly with lightly barred, mottled wings and three tails — the same architecture as a Hex, roughly two sizes smaller. The nymph is a burrower with feathery gills, built to live inside silt rather than on rock.

A burrowing mayfly in the same genus as the Hex and the Brown Drake, pale yellow and off at full dark on summer evenings. Smaller than either and spread thin over weeks rather than concentrated into a week, so it rewards a rod already on the water at dusk.

When it hatches

Peak is June–August. 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.

JFMAMJJASOND

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.

58°F 70°F

Active from 58°F to 70°F. On this map that is cold-transitional, cool, warm water — the band crosses 2 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
nymph	Burrows in silt and soft margins, pumping water through its tunnel. It swims poorly and undulates when it does, so a wiggle nymph fished with pauses is closer to the truth than a dead drift.
emerger	At and after dark, struggling up through the surface. Fish take the emerger hard because the natural is large and helpless.
dun	Pale yellow, big, and on the water at full dark on summer evenings. Spread over weeks rather than concentrated, so it is a hatch found by being on the water rather than by being timed.
spinner	The fall is also after dark, and on many rivers is the better half of the evening.

Matching flies

4 patterns in this book imitate the Yellow Drake, 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 Wisconsin driftless 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.