Hatches

Important Insects for the Midwestern Fly Fisherman

Mayflies
Caddisflies
Midges
Stoneflies
Terrestrials

Mayflies

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

Caddisflies

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.
	Adults	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.
	Egg-Laying	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

Midges

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
Larvae	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.
Pupa	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.
Adults	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

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

Nymph

Kaufmann Stones

GRHE nymphs

Nymphs make good searching patterns. Black and yellow are important in smaller sizes and Black is larger sizes.

Adults

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.

Terrestrials

	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.