Important Insects for the Midwestern Fly Fisherman



When most people think of fly fishing insects, they immediately think of mayflies. Many people plan trips around the predicted hatching dates of certain mayflies. Wisconsin hosts many great hatches and being in between the East and the West, we get hatches associated with both areas. The following table is a small listing of some of the more predictable mayfly hatches.

Common Name Scientific Name Hatch Date Hook Size Patterns Rivers of Note
Hendrickson Ephemerella subvaria early April-mid June 14 Parachutes, Thorax’s, Sparkle Duns Mecan, Brule, Black Earth
Sulphurs Ephemerella Invaria and
Ephemerella dorothea
mid May-mid July 16-18 Sparkle Duns, CDC duns, Parachutes, and Thoraxes Timber Coulee, Wolf River, West Fork
Brown Drake Ephemera simulans mid-June 10 Close Carpet Fly, Hair Wing Adams Wolf, Prairie, Brule
March Brown Stenonema vicarium mid May-mid June 10-12 Catskill, Sparkle Dun, Close Carpet Fly, Hair Wing Adams Brule, West Fork, Wolf, Prairie
Gray Drake Siphlonurus sp. late May-early June 12 Parachute, Thorax Wolf
Light Cahill Stenocron canadense early June-mid August 14 Catskill, Parachute, Thorax, spinner West Fork, Black Earth
Hex Hexagenia limbata mid June-mid July 6 Para-Drake, Emerger, spinner Black Earth, Mecan, White Rivers
Blue Wing Olives Baetis, Psuedocloeon among others all Season 14-26 Thorax, Sparkle duns, parachutes, emergers Most streams
Trico Tricorythodes sp late July-early October 20-24 Spinners, Emergers, Sparkle Duns Timber Coulee, Kinnickinnic, Willow
White Fly Ephoron leukon early August-late September 14 Close Carpet Fly, Parachute, Sparkle Duns Wolf, Prairie, Tomorrow/Waupaca


Few people, including myself, know the Latin names for caddisflies like they do for mayflies, but the can be very important for the fly fisherman. Many streams hold phenomenal numbers of caddis, and they are often the most important insect to imitate. My stream sampling has shown that caddisflies are often the most numerous insects on many Wisconsin streams. The simplest way to imitate caddis is to tie Elk Hair Caddis and variations of the EHC in many sizes and colors. Most common colors are olive, tan, cinnamon, gray, green. For larvae, tie simple flies with dubbed or peacock bodies. The following is a brief outline of patterns that imitate caddis flies.


Stage Type Immitation Notes
Larvae Veggitative-Cased Peeking Caddis These are incredibly numerous. I have found many of the larvae to be a bright green
  Rock-Cased Peeking caddis (light dubbing over silver flash chenille) Believe it or not, trout will eat a caddis living in a rock enclosed case. Give it a try!
  Net Spinning Simple Larval Patterns They spin net to catch food and have leave the security of their shelter to eat. This makes them vulnerable in moderate to fast riffles.
  Free-Living Simple caddis “Worm” patterns Green Rock Worms are probably the most common free-living caddis and are a common trout food
Pupa All Sparkle pupa
soft hackles
and various pupal patterns
I will group all pupa together as they are all similar in appearance. Most common colors are: Yellow, Brown, Orange, Green, Gray, and Black. Pupal colors aren’t always the same as the adult coloration.
Adults Emerging
  • Sparkle Pupa
  • X-caddis
  • Iris Caddis
This is when the caddis is between being a pupa or an adult. Many patterns use zelon to imitate the shuck of the emerging caddis.
  • Elk Hair Caddis
  • X-Caddis and many other adult patterns
Try elk Hair caddis both with and without palmered hackle. Many of the emerging patterns also work as low floating adult imitations. Caddis often hatch quickly, leaving fish little opportunity to feed on the adults.
  • Hackled EHC
  • Diving patterns
As caddis return to the water to lay eggs, they often excite the trout into splashy rises. Some caddis dive underwater to lay egg, the secret is to encapsulate air bubbles in you patterns


Chrinomidges are what we fly fishermen call “midges” and they are a family within the Diptera (True Flies) Order. Many fishermen make the mistake of calling all small flies midges. Midges will hatch almost all year. Most of them are small, but I have seen them up to #16’s. Most of my midge patterns are very simple because there isn’t a lot of hook shank to work with. The larva, pupa and adult stages are all important in midge fishing, but the pupa is probably the most important stage to imitate because this is when they are most vulnerable.

Stage Patterns Notes
  • Fur Larva
  • Krystal Flash Larva
  • Brassies
Larva are very small and simple patterns. There isn’t much more to tying them than making a slender “worm” body. I rarely fish them alone but like to use them on droppers behind a larger nymph.
  • Kimball’s Emerger
  • WD 40
  • Small Humpies
The adult is slow to emerge from the pupal shuck, this makes them very vulnerable. The pupa also rise to the surface making them available to the trout through out the water column.
  • Griffith’s Gnat
  • Simple One Hackle
Midge adults often float for a long time before taking flight. Griffith’s gnat is a cluster pattern that imitates a matting bunch of midges or you can imitate individual adults with simple patterns. Best colors are cream, gray, black, olive, and tan.


Stoneflies are mostly swift water insects and are not as important as many other insects, but Yellow Sallies and Early Black Stones can provide some excellent fishing in Wisconsin’s spring creeks. Stoneflies are likely much more important on Northern Wisconsin’s freestone rivers, but I haven’t experienced a real hatch there.

Stage Patterns Notes
  • Kaufmann Stones
  • GRHE nymphs
Nymphs make good searching patterns. Black and yellow are important in smaller sizes and Black is larger sizes.
  • Stimulators
  • Elk Hair Caddis
Black stones in #16-18 are important early and Yellow Sallies are sizes 12-14 and are a dependable summer hatch. Salmonflies are not a fishable hatch here, though I have found the nymphs.


  Time of year Notes
Grasshoppers Mid-July to end of season The most used terrestrial and some of the most explosive fishing of the year. I prefer foam flies (particularly my “Featherweight Foam Hopper”) though many commercial patterns work well.
Crickets Late June to end of season Overlooked by most but a very consistent “hatch”. They make a great searching pattern on our spring creeks. Any foam fly works well for me.
Ants May to end of season Trout love ants! Foam or fur ants fished below trees, bushes and over hanging grasses are deadly. Also a killer fly during a heavy hatch.
Beetles May to end of season Another underutilized pattern. Simple foam flies are great searching patterns. Fish them below trees, bushes, and overhanging grass.