Michigan Flies

Hatches / mayfly

Mahogany Dun

A

Paraleptophlebia / Neoleptophlebia spp., fall brood (species not confirmed by Michigan sources)

Also called Fall Mahogany, Small Slate Mahogany, Paraleptophlebia.

The small dark mayfly that brings trout up on fall afternoons after the Tricos and before the season closes, mid-September through October on the Pere Marquette and, by the U.P. chart, into November farther north. Duns emerge in slower water and eddies during the warmest part of the day, when they overlap the fall Blue-Winged Olives; a #16-18 mahogany or rusty parachute solves the fish that refuse an olive. Fish a small dark nymph on the edges beforehand and a rusty spinner late in the afternoon. On the Upper Manistee, mahogany duns are also listed among the May-June hatches, where the Blue Quill record applies.

#16–18middayafternoonnymphemergerdunspinnermahogany to reddish-brown bodyslate gray wingrusty spinner

© Lauren · CC BY · iNaturalist · Haight Township, MI · 2025

Timing by region

  1. Southeast Lower Peninsula
    1. J
    2. F
    3. M
    4. A
    5. M
    6. J
    7. J
    8. A
    9. S
    10. O
    11. N
    12. D
    Window
    Aug 18 – Oct 17
    Peak
    Sep 1 – Oct 1
  2. Southwest Lower Peninsula
    1. J
    2. F
    3. M
    4. A
    5. M
    6. J
    7. J
    8. A
    9. S
    10. O
    11. N
    12. D
    Window
    Aug 22 – Oct 21
    Peak
    Sep 5 – Oct 5
  3. Northeast Lower Peninsula
    1. J
    2. F
    3. M
    4. A
    5. M
    6. J
    7. J
    8. A
    9. S
    10. O
    11. N
    12. D
    Window
    Sep 1 – Oct 31
    Peak
    Sep 15 – Oct 15
  4. Northwest Lower Peninsula
    1. J
    2. F
    3. M
    4. A
    5. M
    6. J
    7. J
    8. A
    9. S
    10. O
    11. N
    12. D
    Window
    Sep 1 – Oct 31
    Peak
    Sep 15 – Oct 15
  5. Upper Peninsula
    1. J
    2. F
    3. M
    4. A
    5. M
    6. J
    7. J
    8. A
    9. S
    10. O
    11. N
    12. D
    Window
    Sep 22 – Nov 21
    Peak
    Oct 6 – Nov 5
  6. Pere Marquette Riverlocal chart
    1. J
    2. F
    3. M
    4. A
    5. M
    6. J
    7. J
    8. A
    9. S
    10. O
    11. N
    12. D
    Window
    Sep 15 – Oct 31
    Peak
    —

Flies that match

Pheasant Tail Nymph (reference photo)Reference photo
Pheasant Tail Nymph
A
Nymph#10–20NaturalBeadheadFlashback

Old Au Sable Fly Shop names a #12 to #14 Pheasant Tail as the Hendrickson nymph, and it covers every Michigan Ephemerella and Baetis nymph before and during a hatch. A beadhead #10 is a standard trailer fly in U.P. steelhead rigs, and #12 to #20 versions take pink salmon in clear water. Fish it dead-drifted under an indicator or on a tight line in the weeks before each mayfly hatch.

Indicator nymphing · Euro / tight-line nymphing

Reserve · $2.75
Borchers Parachute (reference photo)Reference photo
Borchers Parachute
A
Dry fly#10–16Dark turkey-quill body, brown hackle

Grayling's dark all-purpose mayfly, listed by Hawkins in #10 to #16 for Mahogany and Isonychia spinners. It doubles as a Hendrickson and Black Quill dun in spring and a fall Mahogany Dun on the Pere Marquette from mid September through October. Fish it at dusk for Iso spinner falls from June through September.

Dry fly

Reserve · $3.00
Mahogany Dun Parachute (reference photo)Reference photo
Mahogany Dun Parachute
A
Dry fly#14–18Mahogany body, slate wing

For the fall Mahogany Duns that draw feeding fish on the Pere Marquette from mid September through October, and the Slate Wing Mahoganies of U.P. charts. Fish it on cool afternoons in slow seams; it also matches the spring Blue Quill in #16 to #18.

Dry fly

Reserve · $3.00