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 NameScientific NameHatch DateHook SizePatternsRivers of Note
HendricksonEphemerella subvariaearly April-mid June14Parachutes, Thorax’s, Sparkle DunsMecan, Brule, Black Earth
SulphursEphemerella Invaria and
Ephemerella dorothea
mid May-mid July16-18Sparkle Duns, CDC duns, Parachutes, and ThoraxesTimber Coulee, Wolf River, West Fork
Brown DrakeEphemera simulansmid-June10Close Carpet Fly, Hair Wing AdamsWolf, Prairie, Brule
March BrownStenonema vicariummid May-mid June10-12Catskill, Sparkle Dun, Close Carpet Fly, Hair Wing AdamsBrule, West Fork, Wolf, Prairie
Gray DrakeSiphlonurus sp.late May-early June12Parachute, ThoraxWolf
Light CahillStenocron canadenseearly June-mid August14Catskill, Parachute, Thorax, spinnerWest Fork, Black Earth
HexHexagenia limbatamid June-mid July6Para-Drake, Emerger, spinnerBlack Earth, Mecan, White Rivers
Blue Wing OlivesBaetis, Psuedocloeon among othersall Season14-26Thorax, Sparkle duns, parachutes, emergersMost streams
TricoTricorythodes splate July-early October20-24Spinners, Emergers, Sparkle DunsTimber Coulee, Kinnickinnic, Willow
White FlyEphoron leukonearly August-late September14Close Carpet Fly, Parachute, Sparkle DunsWolf, 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.

 

StageTypeImmitationNotes
LarvaeVeggitative-CasedPeeking CaddisThese are incredibly numerous. I have found many of the larvae to be a bright green
 Rock-CasedPeeking 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 SpinningSimple Larval PatternsThey 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-LivingSimple caddis “Worm” patternsGreen Rock Worms are probably the most common free-living caddis and are a common trout food
PupaAllSparkle 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.
AdultsEmerging
  • 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.

StagePatternsNotes
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.

StagePatternsNotes
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 yearNotes
GrasshoppersMid-July to end of seasonThe 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.
CricketsLate June to end of seasonOverlooked by most but a very consistent “hatch”. They make a great searching pattern on our spring creeks. Any foam fly works well for me.
AntsMay to end of seasonTrout love ants! Foam or fur ants fished below trees, bushes and over hanging grasses are deadly. Also a killer fly during a heavy hatch.
BeetlesMay to end of seasonAnother underutilized pattern. Simple foam flies are great searching patterns. Fish them below trees, bushes, and overhanging grass.