Early Brown Stonefly hatch is one of the earliest hatches where you might get a chance to fish for rising trout on a freestone stream in NorthWest Wisconsin. The hatch occurs from mid-March into mid-April depending on the temperatures, Winter snow amounts and the stream location. Before the Wisconsin DNR started the early season catch & release we never got a chance to experience this wonderful early season stonefly hatch.
The small stonefly nymphs crawl out of the water along the shoreline to shuck its nymphal case usually during the warmest part of the day. The stoneflies come back on the water to lay their eggs (ovipositing) and flutter and skate across the surface. Especially in midday and early afternoon you can find these bugs flying about and landing on the water, but it does depend on the seasonal weather. This can make for some great early season dry fly action to rising trout.
The early brown stonefly measures 5/8" long from head to the end of it's grayish-brown wings. The blackish body is only about 3/8" long.
When the stoneflies are not fluttering on the water I use a small stonefly nymph pattern (see below) along with a strike indicator. My preferred pattern when the stoneflies are on the water ovipositing is a size #14 Mustad 94840 dry fly hook, with a CDC body, a teal flank feather for the wing (tied flat) and sparsely tied grizzly hackle. When the stoneflies are fluttering on the water and getting the trout's attention I prefer a palmered hackle dryfly with a light grayish deerhair wing and well hackled in the front as well to help skitter the dry fly pattern on the water.