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