Hendrickson Hatch (Ephemerella subvaria): The First Real Spring Mayfly of the Inland Trout Year
Hendricksons are the classic eastern spring mayfly hatch -- mid-April through May on SHA-region inland trout streams, water temperatures around 50-55 degF, late-afternoon emergence with substantial dry-fly fishing. Male duns + the famously pink-bodied "Pink Lady" females. The first reliable surface fishing of the inland trout year.
TL;DR
Identification
- Body color: male duns brownish-red; female duns lighter tan with reddish thorax. Spinners (mature adults): male rust-brown; female pink-bodied.
- Wing color: slate gray on duns; clear with dark venation on spinners.
- Size: body length 8-12 mm; hook size 12-14.
- Tails: three; characteristically banded with dark + light segments.
- Body shape: stocky mayfly; pronounced thorax.
Timing
| Geographic onset | Mid-April in southern PA + OH water; late April in WNY + northern PA. Trigger: water temperature 50-55 degF. |
| Peak weeks | Late April through mid-May. |
| Tail-off | Mid-May to early June. |
| Daily timing | Duns: 2 p.m. to 5 p.m. typical. Spinner fall: 6-8 p.m. |
| Weather trigger | Warm overcast spring afternoons + light rain produce the strongest emergences. |
Tactics + flies
- Dun patterns: Hendrickson Comparadun + Parachute Hendrickson + Catskill-style Hendrickson dries. Size 12-14.
- Pink Lady spinner patterns: distinctive pink-bodied spinner for the female spinner fall. Size 12-14.
- Male spinner patterns: standard rust-brown spinner patterns.
- Emerger patterns: Klinkhamer + soft-hackle wet flies for the surface-film transition.
- Nymph patterns: pheasant tail + Hare's Ear in the appropriate size during the days leading up to + including the hatch.
- Tippet: 5X; 4X for larger or more aggressive water.
SHA-region waters
Hendricksons hatch on virtually every quality inland trout stream in the SHA region. Strong populations on PA Class A streams (Oil Creek + French Creek + ANF tribs), WNY Wiscoy + Genesee headwaters, and OH Clear Fork Mohican. See the Class A near the Alley pillar for water context.
Honest gaps
- Multiple Ephemerella species + closely related Eurylophella + Drunella species lumped under "Hendrickson" by anglers.
- Site-specific timing varies; field observation is authoritative.
Full source list
- Tier 3 -- entomological reference: Ephemerella subvaria + Ephemerellidae family literature.
- Tier 1 -- state agency hatch reference where published.
Common questions
Why is the Hendrickson called "the first real hatch"?
BWO + small black stones + midges precede the Hendrickson but the Hendrickson is the first substantial hatch where SIZE 12-14 mayflies are present in numbers; the larger fly size makes it the first hatch most anglers fish seriously.
What's a Pink Lady?
The female Hendrickson spinner has a distinctive pink-orange body color. The spinner fall produces some of the most photographed dry-fly fishing in eastern angling literature.
How long does the Hendrickson hatch last on a given stream?
Roughly 3-4 weeks of fishable activity. Daily emergence is 2-3 hours; spinner fall an additional 1-2 hours.
Image credits and licensing
- Inline image: Hendricksons are spiny crawler mayflies; their nymphs live in the stream long before the famous spring dry-fly window. Photo: Bob Henricks / Wikimedia Commons, CC BY-SA 2.0.
- Hero image: Photo: Bob Henricks / Wikimedia Commons, CC BY-SA 2.0.
