Now that the end of July is here, many fly fishers mourn the passing of the fat hatches of spring. I don’t. I’m excited because my best days of this trout season are still ahead. All year I’ve been looking forward to sultry July and August mornings with the sun rising over a watercress meadow, burning orange through the heavy, humid air. Trico time is my time.
To me, the most attractive aspect of this extraordinary hatch is that it provides the average angler a fair shot at taking an above-average trout on a tiny dry fly. Knowing a few things how the Trico hatch unfolds will help you out.
1. A KNOWLEDGE OF SEX HELPS. During the heat of the summer, prime Trico time, male Tricos emerge from the water first, often beginning just after sunset and continuing throughout the night. (Yes, some hard-core anglers do fish then.) The females hatch the following morning beginning at daybreak. This is an important bit of intelligence because, when you get to the water and start stripping line off your reel first in the morning, very few male duns may be on the surface; they’ll already be up in the trees, molting. An imitation of a female dun is naturally your best offering. In cooler climates or later in the season, the emergence of male duns is typically delayed to just before sunrise, followed directly by the female duns. In these circumstances, both males and females will be on the water at the same time.
2. ON A NORMAL, WARM SUMMER MORNING, the male spinners fill the air by 7 a.m. By 8:30 a.m. the first of the spinners fall to the water. A heavy spinnerfall usually lasts several hours. Sometime during the morning both male and female duns molt into spinners. When the female duns begin to emerge, the male spinners start to swarm high over the riffles and along the banks on larger waters. Air temperature determines when the female duns molt into spinners. Warmer air temperatures mean an earlier molt, opposite for cooler temperatures. So, the female duns may molt within minutes or hours after hatching. Once molting has occurred, the female spinners fly into the swarms where the males grasp them and mating takes place. After mating, the male spinners immediately fall to the water and are taken by awaiting trout. The female spinners make for vegetation where they wait for their egg-sacs to develop, then head back to the water to lay their eggs, finally drifting spent as well.

Mike & the Trico hatch.
The trout are highly attuned to this sequence. Watch how their behavior changes as the morning progresses. After two or three Trico mornings, you should pick up on their transition from feeding on duns to feeding on spinners. If you’re unable to detect a change, look closely at the water and see if there are duns or spinners drifting downstream. At first a few trout switch their attention, then nearly all will be feeding on spinners. Remember that the males fall to the water first. During the early stages of the spinnerfall, trout will be taking male spinners exclusively, making the male spinner imitation your best bet. Before the female spinners fall to the water, they will fly back and forth above the stream, an indication for you to be ready with female spinner imitations. If you don’t notice the female flights, look to the water to determine what is adrift.
As the weather turns colder, spinnerfalls become lighter and later in the day. On autumn days I’ve seen good clouds of spinners not begin to fall until after the noon hour. Air temperature will determine when. My advice is to check your weather channel the night before—or simply show up early and enjoy a cup of coffee along the stream while waiting for Nature’s dance to unfold.
3. TIMING IS EVERYTHING. Trout go crazy when these tiny mayflies hit the water. Some remarkably large fish will move from their protective shelters and position themselves in plain sight, just below the surface, to dine on the parade of the dark-bodied flies with gossamer wings. Although normally calm pools are now erupting with energetically rising trout, don’t delude yourself about the ease of hooking one! Stop everything and watch. You’ll notice that many fish are rising routinely, some every few seconds. Get a feel for the rhythm of your target fish, then time your cast and the anticipated drift of your fly precisely with the next time you expect the fish to rise.
4. PAY ATTENTION. Feeding trout may be taking emergers, duns or spinners; only the keen eye of a patient angler will discern which. Careful observation will be your missing link. The all so common “head and tail” rise form will usually be seen if the trout are taking duns and spinners. Or sometimes just the nose of the trout will break the water’s surface. Emergers are taken just below or very low in the water’s surface. For the most part, trout won’t break the surface when feeding on emergers. Many times these riseforms are just a slight dimple seen on the surface.
5. EASY DOES IT. A trout feeding on Tricos will move only inches to sip the next morsel—or your fly. Imagine your window of opportunity as a 10-inch pie plate immediately upstream from a rising trout. Your fly needs to land within that window and fall as gently as dandelion fluff. A delicate cast that’s right on target is vital. Your leader must be long: at least 10 feet and finished with an ultra-fine tippet of 6X, 7X or 8X. I use only SA Absolute Trout for my leaders and either SA MPX or Absolute Trout Fly Line.
Check out my website at www.fallingsprings.com for all the flies you may need or book a trip with me so we can fish these wonderful Tricos together.
About the Author:
Mike is the owner of Mike Heck’s Trout Guides in Fayetteville, PA and also works and guides for Precision Fly and Tackle located in Mt. Holly Springs, PA, Lancaster, PA and Boonsboro, MD.
Mike has been fly fishing his beloved Cumberland Valley, Pennsylvania streams since boyhood. He was blessed to have been able to learn the art of fly fishing on some of the hardest and most famous spring creeks in the country. He has been doing so for over thirty years.
Mike is a graduate of Penn State University where he acquired his degree in Forestry. This degree has allowed him to become more knowledgeable about the delicate balance between foliage, insect and stream interaction, which has in turn enabled him to become a superior fly fisherman and trout guide.
He is the author of, “Spring Creek Strategies”, Co-Author of “Tying Dry Flies” and “Keystone Fly Fishing.” He has also had articles published in FLY FISHERMAN, AMERICAN ANGLER and FISH AND FLY magazines. Mike has appeared in “Road Trip USA”, a Discovery Channel TV show that aired across Europe.
Mike is also an innovative fly tyer with several patterns credited to his name. His signature fly patterns are famous and used worldwide by all types of fly fishermen. All these fly patterns are available through his website www.fallingsprings.com.
Mike offers guiding for the Falling Springs, Big Spring, Letort, Yellow Breeches and many other great trout streams in South Central Pennsylvania. You can find Mike Heck’s Trout Guides on the web at www.fallingsprings.com, or contact him by e-mail at fallingsprings@outlook.com. You may also call him at (717) 321-5160.