Wisconsin Fly Fishing for Trout

Northern Wisconsin Trout Stream Mayfly Hatch Chart

Below are listed the most common Wisconsin mayfly hatches created by John Simonson (WiFlyFisher). This is mainly for the northwest Wisconsin and central Wisconsin trout streams, such as: the Namekagon River, Bois Brule, Prairie, Wolf, etc.).

The X's represent individual weeks within a given month and the approximate emergence time for each mayfly. The hatch dates will vary from year to year depending on the weather conditions, seasonal climate changes, type of stream, etc.

Northern Wisconsin Mayfly Hatches

Common Name Scientific Name / Details Mar Apr May Jun Jul Aug Sep
Blue Wing Olives (BWO)(2) Baetis
size:6-7mm (#18 -#22)
nymphs 3 tails (middle tail shorter)
adults 2 tails
--XX XXXX XXXX XXXX     XXXX
Gray Drake Siphloplecton basale
size: 14-16 mm (#8)
nymphs 3 tails / duns 2 tails
  --X X--        
Hendrickson Ephemerella subvaria
size: 10-12 mm (#12)
nymphs 3 tails / duns 3 tails
  --XX XX--        
Sulphurs Ephemerella invaria / rotunda / excrucians
size: 9-10 mm (#14)
nymphs 3 tails / duns 3 tails
    --XX X---      
Sulphurs Ephemerella dorothea
size: 6-7 mm (#18)
nymphs 3 tails / duns 3 tails
    --XX XX---      
Black Quill Leptophlebia cupida
size: 10-11 mm (#12)
nymphs 3 tails / duns 3 tails
    --XX X---      
Gray Drake Siphlonurus alternatus
size 12 -16 mm (#8)
nymphs 3 tails
duns / spinners 2 tails
    --XX XX---      
Little Dark Hendrickson Ephemerella needhami
size: 9-10 mm (#14)
nymphs 3 tails / duns 3 tails
    ---X XX-      
Sulphur Epeorus vitreus
size 9 - 12 mm
nymphs 2 tails / duns 2 tails
    ---X XX-      
March Brown / Gray Fox Maccaffertium vicarium
(formerly Stenonema)
size 14-16 mm (#10 2x long)
nymphs 3 tails (clingers)
duns 2 tails (speckled wings)
    ---X XXX-      
Armored Speckled-Wing Baetisca laurentina
size 10-12 mm (#12)
nymphs 3 tails (fat body)
duns 2 tails (chubby mottled wing)
    ---X XXX-      
Light Cahill Stenacron / Maccaffertium
(several species)
size 9-1 mm (#12 2x long)
nymphs 3 tails (clingers)
duns 2 tails (speckled wings)
      XXX-      
Darth Vader Serratella deficiens
size: 4-5 mm (#20)
Blackish wings
pale yellow legs
nymphs 3 tails / duns 3 tails
      XXX-      
Brown Drake(1) Ephemera simulans
size 12-15 mm (#10 2x long)
nymphs 3 tails (burrower)
duns 3 tails (brown splotch wing)
      XXX-      
Hex Hatch
Michigan Caddis(1)
Hexagenia limbata
size 16-35 mm (#6)
nymphs 3 tails (burrower)
duns 3 tails
      --XX X---    
Mahogany Dun Isonychia bicolor
size 13-16 mm (#8 2x long)
nymphs 3 tails (swimmers)
duns 2 tails
      ---X XXXX XX--  
Tricos Tricorythodes minutus
3 -3 1/2 mm (#22 - #24)
nymphs 3 tails
adults 3 tails
        -XXX    
Large Rusty Spinner(1) Hexagenia atrocaudata
size 16-30 mm (#6)
nymphs 3 tails (burrower)
duns 3 tails
        --XX X---  
Little Yellow Quill Leucrocuta hebe
size 9-12 mm (#12)
duns 2 tails
duns yellow body & orange thorax
        ---X XXX-  
White Mayfly(1) Ephoron leukon
size 10-13 mm (#12)
nymphs 3 tails (burrowers)
duns 2 tails (white body)
          XXX-  
Common Name Scientific Name / Details Mar Apr May Jun Jul Aug Sep

Notes:
(1) - indicates mayfly nymphs that burrow in sand, silt and muck. The densest hatches for these insects will occur in those stretches of the stream.

(2) - there are several mayflies species that all fall under Blue Wing Olives (BWO) and hatch at different times during the season. Some I see are too sporatic to really get the trout's attention.

See also: General Characteristics for Mayfly Species of Northern Wisconsin

Northern Wisconsin Trout Stream Caddis Hatches (Sedge)

I don't know the scientific names for most of the dominant caddisfly hatches, but do not under-estimate the importance of these little fluttering critters. On many of the Wisconsin freestone streams that I frequently fly fish for trout there are numerous caddisfly hatches that trigger heavy trout feeding. Some of my favorite caddisfly hatches are the Grannom (Brachycentrus), Green Sedge (Rhyacophilia), Dark Green Sedge (?), Little Black Sedge (Chimarra), Spotted Sedge (Hydropsyche), Ginger Sedge (?) and Great Brown Sedge (Pycnopsyche). You can find caddis on the rivers pretty much all summer long from East Coast to the West Coast. I prefer tightly wrapped wool for the larva stage, Gary LaFontaine's Emergent Sparkle Pupa or a small bead head, gold-ribbed hare's ear for the emerging caddis, and elk hair caddis, or diving bead head caddis for the adults. See the Caddisfly page for more information.


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Page Reviews
Web Page: Northern Wisconsin Trout Stream Mayfly Hatch Chart
by
Overall Rating: 5.0 stars - 4 reviews

Paged Reviewed: Northern Wisconsin Trout Stream Mayfly Hatch Chart
Reviewed By: Joe Hawkins
Page Rating: 5.0
Review Date: 16 May 2012
Page Review:
This is great mayfly hatch chart!! Thank you WiFlyfisher!
Paged Reviewed: Northern Wisconsin Trout Stream Mayfly Hatch Chart
Reviewed By: B Towle
Page Rating: 5.0
Review Date: 3 January 2014
Page Review:
This is extremely helpful. I'm hoping to get started on fly fishing for trout in NW WI and this will help greatly.
Paged Reviewed: Northern Wisconsin Trout Stream Mayfly Hatch Chart
Reviewed By: Matt
Page Rating: 5.0
Review Date: 15 February 2014
Page Review:
Overall a very nice presentation of the Wisconsin mayflies. BTW the East Branch of the Delaware has a very intense emergence of simulans in early June for about two weeks. Huge rafts of duns come down river. In the beginning the big browns are gluttons but soon become wise to patterns that don't look very good or have drag in the cast.
Paged Reviewed: Northern Wisconsin Trout Stream Mayfly Hatch Chart
Reviewed By: Jim S
Page Rating: 5.0
Review Date: 29 December 2015
Page Review:
Great hatch chart. Appreciate it.
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