Northern Wisconsin Mayfly Hatch Chart

Below are listed the most common Wisconsin mayfly hatches that are important to fly fhsermen. The chart was created from my many years studying the aquatic insects found in our northern Wisconsin trout streams. The mayfly hatch chart covers the northern Wisconsin and central Wisconsin trout streams, such as: the Namekagon, Bois Brule, Prairie, Wolf, Oconto, Phestigo, Pine, 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

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 Caddisfly Hatches (Sedge)

Below is a listing of the most common Northen Wisconsin caddisflies that are found in our freestone streams that may have importance to fly fishermen in different stages of their lifecycle.

• Little Black Caddis
• Little Short-Horn Sedge
• American Grannom
• Spotted Sedge
• Green Sedge (Green Rock Worm / Apple Caddis)
• Little Sister Sedge
• Long-Horned Sedge
• Little Plain Brown Sedge
• Zebra Caddis
• White Miller
• Giant Rusty Sedge
• Great Brown Autumn Sedge (large stick cases)
• Little Dot-Winged Sedge

See also: Lifecycle of Caddisflies for more detailed information.