Hexagenia
Also called Hex, Hex hatch
Hexagenia are large burrowing mayflies (the “hex” hatch). Their nymphs live in soft-bottom lakes and slow rivers, and the adults can bring big trout up to feed after dark.
- Group
- Mayfly hatches
- Category
- Entomology & forage
- Level
- Intermediate
- Water
- Freshwater
Last updated
What Hexagenia means
Think big mayflies and warm nights. Hexagenia is a genus of burrowing mayflies whose nymphs live in mud or silt, often in lakes, reservoirs, and slow river sections with soft bottoms.
The nymphs spend most of their lives in U-shaped burrows and feed on fine organic material. When they’re ready to hatch, they swim or crawl up out of the bottom and emerge near the bank, in weed beds, or along soft shorelines. On many waters the main activity is late evening into dark, followed by a spinner fall that may happen the same night or the next.
Because the bugs are large, the imitations are large too. Anglers usually cover the hatch with a mix of nymphs (before and during emergence), emergers/duns around dusk, and spinners later when the spent adults collect in slicks and along edges.
Why it matters on the water
Hex fishing is often about timing and location more than perfect pattern match. Soft-bottom structure, weed lines, and gentle current seams are the places to look, and the window can be short—especially if the main emergence happens after sunset.
Tackle and presentation change with the bug size. Bigger flies land harder and twist lighter leaders, so most anglers step up tippet strength and slow down the cast. Good light management matters too: a headlamp used sparingly, a plan for landing fish in the dark, and a clear wading line before it gets late.
Read next
- Green drakeA “green drake” is a large mayfly hatch that can bring trout to the surface for big dry flies, especially in late spring and early summer. The name is used for several similar-looking mayfly species depending on the region.
- Pale morning dunA “Pale Morning Dun” (PMD) is a common mayfly hatch made up of small, pale yellow mayflies. Anglers use PMD nymph, emerger, dun, and spinner patterns to match it.
- SpinnerA spinner is a dry fly that imitates an adult mayfly after it has mated and fallen spent on the water, usually with wings laid flat to the sides.
- TricoTrico is a tiny mayfly (genus Tricorythodes) best known for dense summer morning hatches and spinner falls. On many trout rivers it brings selective fish and fine-tippet dry-fly fishing.