Adult

Hatches › Mayfly

Mayfly

Gray Drake

Siphlonurus · genus

Gray Drakes are big, primitive minnow mayflies that give trout a highly visible mayfly meal.

Overview

About Gray Drake

Siphlonurus is a genus of mayflies in the family Siphlonuridae, a group often called primitive minnow mayflies. For anglers, Gray Drakes matter as larger-profile mayflies that can be imitated effectively in nymph, emerger, dun, and spinner stages.

Also known as: Grey Drake

Life Cycle

Eggs

Female mayflies deposit hundreds to thousands of eggs either in or near the water. These eggs then sink to the stream bed, where they will hatch.

nymph

Mayfly nymphs reside on the streambed, where they feed and grow. This aquatic stage involves numerous molts before they mature.

emerger

As the nymph matures, it rises to the water's surface, where it begins the process of hatching into its adult form.

Dun / Adult

The freshly emerged adult, known as a dun, rests temporarily on or just above the water surface before its final molt.

spinner

After their final molt, fully matured adult mayflies, now called spinners, take to the air to mate and complete their reproductive cycle.

Egg Laying Spinner

The female spinner returns to the water's surface specifically to deposit her eggs, initiating the next life cycle.

Spent Spinner

Once egg-laying is complete, the adult mayflies die and often drift on the water's surface, making them an easy meal for fish.

Stages: Anglers commonly fish the nymph, emerger, dun, and spinner stages.
Emergence cues: Look for activity in the broader spring-to-summer window, especially during mild conditions when mayflies begin showing on the surface; low light and calmer periods can concentrate emergence or spinner activity.
Behavior: Nymphs are available subsurface until emergence. Emerging insects pause in or just under the film, duns ride the surface before flying off, and spent spinners can fall flat and collect in softer surface lanes.

How to Tie Gray Drake Patterns

nymph

Beginner Fly Tying a Grey Nymph with Jim Misiura

Jim Misiura

Materials

HookStd 2xl Nymph #12 - #18
BeadMatch Hook Size
ThreadBlack
TailGrizzly Hackle
BodyGrey Dubbing (Natural Preferred)
HackleGrizzly

emerger

Fly Tying the Lord Gray (AP Nymph Pattern)

Savage Flies

Materials

Hook#12-181x long nymph
ThreadGray
TailPartridge fibers
RibSilver wire
BodySquirrel dubbing
WingcasePartridge fibers
ThoraxSquirreldarker than body
HacklePartridge

spinner

Muskegon Gray Drake Spinner (Updated)

George Leonardos

Materials

Hook#10 - extra long
Uni thread#6SOT black
WireExtra fine gold
DubbingBlack, for body and thorax
Hackle fibersVariegated, stiff, about the length of the hook

Egg Laying Spinner

Foam Body Gray Drake: Dry Fly Tying Tutorial

Caddis Fly Angling Shop

Materials

HookSize 12Tiemco 100
ThreadSemperfli Nanosilk 50 Denier - black
Elk HairNature’s Spirit Elk Hair - tail, black
Foam2mmHareline 2mm Fly - Grey, Abdomen
Mono.2Veevus Mono - Black, Abdomen
Wing MaterialMontana Fly Company Widow’s Web, Smoke
UV ResinSolarez Bone Dry
DubbingHareline Micro Fine Dubbing, Trico, Thorax

Spent Spinner

Muskegon Gray Drake Spinner (Updated)

George Leonardos

Materials

Hook#10 extra long
Thread6/0Uni SOT Black
WireGold, extra fine
DubbingBlack, for body and thorax
HackleVariegated hackle fibersstiff, about the length of the hook

Where It Hatches

Gray Drake

One species, multiple rivers.

River

Fly Patterns

Gray Drake Dry#10-12

Angler Notes

Why it matters: Gray Drakes are worth noticing because they offer trout a larger mayfly target, and fish often key on them confidently when insects are trapped in the film or collecting on calmer water.
Imitation tips: Carry a simple progression: a larger mayfly nymph, a floating emerger, a comparadun or traditional dun with gray tones, and a low-riding spinner. Match the general gray-brown silhouette and size before worrying about fine color details.
Key life stages: nymphemergerdunspinner
Presentation: Dead-drift nymphs near softer edges and transitions, then switch to emergers or duns when surface activity starts. For spinner falls, use a quiet, drag-free drift over slicks, eddies, and gentle seams where spent insects gather.

Identification

Key features: A relatively large, slender mayfly with an elongated body, upright wings as a dun, and long tails; overall profile is more substantial than many small mayflies trout see daily.
Size: Generally a larger mayfly impression; common fly patterns are often tied around sizes 10-14.
Coloration: Usually matched with gray to smoky wings and a gray-brown to olive-brown body, with spinners often appearing a bit clearer and darker in silhouette.
Similar bugs: Green DrakeBrown DrakeMarch BrownMahogany Dun

Habitat

Water types: riversstreamslakespond marginsslow backwaters
Substrate: Weedy areas, soft bottoms, and slower margins or flats where nymphs can develop away from heavy main-current churn.
Conditions: Most relevant where there is moderate to slow water, soft current seams, or stillwater edges that allow emergers, duns, and spinners to linger.