Green Drake (Ephemera guttulata)

Mayfly, hatching May–June, active in water between 52 and 64°F, and imitated at #8–12. Recorded from the Virginia mountains, where 796 Virginia rivers on this site carry a page.

The largest mayfly of the eastern hatch calendar, pale yellow-green with heavily mottled wings, peaking in May and June on water between 52 and 64 degrees — cold, cold-transitional and cool alike. It is an Appalachian freestone event that lasts a week or two at most, and in the mountains its arrival shows up on shop calendars a year in advance. The nymph burrows in silt and gravel margins, pale and gilled. The emergence is a big insect struggling out of a big shuck in the film, one of the few in which fish will take a badly presented fly. The dun is cream-green with mottled wings at size 8 to 12, and nothing else on the water looks like it. After dark the spinner returns as the Coffin Fly: white body, black legs, clear wings. A Green Drake or Coffin Fly dry at 8 to 12 matches it; a Stimulator, 8 to 16, and a Hare's Ear Nymph, 10 to 18, fill in around it. The records here cover only the Virginia and North Carolina mountains.

#8–12Hook size
52–64°FWater, active
May–JunPeak months
4Life stages fished

Subbasins with trout water where it is on record: 29 of Virginia's 53.

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

What it is

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

The largest mayfly of the eastern hatch calendar, pale yellow-green with heavily mottled wings. In the mountains its arrival is an event that shows up on shop calendars a year in advance.

Appalachian freestone event, a week or two at most. The spinner — the Coffin Fly — comes back at dusk.

When it hatches

Peak is May–June. 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.

52°F 64°F

Active from 52°F to 64°F. On this map that is cold, cold-transitional, cool 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	A burrower in silt and gravel margins, pale and gilled.
emerger	A big insect struggling out of a big shuck in the film — one of the few emergences where fish will take a badly presented fly.
dun	Cream-green body, mottled wings, size 8 to 12. Nothing else on the water looks like it.
spinner	The Coffin Fly: white body, black legs, clear wings, falling after dark.

Matching flies

4 patterns in this book imitate the Green 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.

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.