Summers Buffet

As we trudge our way through a warm, dry summer I am reminded that Mother Nature does things very much by design. River temperatures are at their coolest on summer mornings. It makes sense, then, that the best insect hatch on our trout waters take place in the morning hours during summer. Trout will be more active and be able to digest their meal more effectively in these reduced water temperatures.

From mid July on into September the most consistent hatching (and mating spinner falls) activity is provided by the tiny but prolific mayfly we anglers call "tricos". It is perhaps my favorite fishing activity of the season for its consistency and also its challenges.

The piece below originally appeared in the Manchester Journal in July of 2017 when I was the freelance fishing writer for the paper. It is a two piece article that I have updated a bit since it first appeared. The first installment is shared below. The second installment will follow in a few days.

An individual fish rises on a misty August morning. The early rising angler has the opportunity to catch a fish or two to trout taking the emerging female duns.

With the departure of July, we are entering the most challenging time of the year for Battenkill fly anglers. As hard as it may seem to believe in this season of shrunken flows, the best dry fly fishing of the year is at hand. How can that be? The answer is captured in one word: Trico (short for the tongue twisting name of the natural insect - Tricorythodes). This is very simply the most consistent, prolific and longest lasting mayfly emergence on the Battenkill and other local rivers. Dry fly opportunities exist from July on into the middle of September at a minimum. With our milder and extended fall weather the bugs are now persisting into October.

While the dry fly fishing is indeed excellent, it is an often a frustrating ordeal. Because trout see literally millions of these diminutive flies over the course of their extended emergence and subsequent mating spinner falls, the fish become increasingly particular about what counterfeit flies they will take. Add to this a cruel twist and as July slips into August our trout become increasingly difficult to fool. For many anglers, this fishing is more than they care to get involved with. For the fly fisher seeking the ultimate challenge in fine tackle, tiny flies and rising trout; this is a cherished time of year.

Lets begin our discussion of trico fishing with a little bit about the nature of the insect we seek to imitate. To begin with, these flies are small. The angling literature tells us the flies are imitated on size 20 - 26 hooks. In this region, I see the # 22 hook as the staple at the beginning of the hatch in July. By mid August it is often necessary to go down to a # 24 fly.

Tricos have an interesting emerging pattern, with the male duns hatching after dark well into the night. The male duns have no value to the angler, as a result. The female duns begin hatching at dawn and can continue to emerge even as spinners have begun to gather over the water. While most anglers will target the prolific spinner falls, the early rising angler can target sporadically rising fish that are feeding on the duns. A simple fly with a pale olive body and pale dun hackle does well at this time.

Female trico duns have an olive body and a light dun wing. If you wish you can incorporate the black thorax into into your pattern. I generally don't.

Even as the females are emerging, the males have already transformed into their spinner form and can be seen dancing above sun splashed riffles day after day and week after week. The trout begin to anticipate this and can sometimes be seen finning just under the surface in anticipation of the spinner fall to come. These same fish will also pick off the occasional dun as it drifts by.

Imitating the female trico dun does not have to be overly complicated. The above pattern has brought plenty of fish to the surface for me.

While the duns can offer a bit of angling it is the spinner fall that truly matters with this mayfly. For years I would get up with the sun, fish duns for a bit and then wait for what seemed like forever as I watched spinners dance above the water. Some days the flies would get on the water early (say 8 am) while on others (often the very next day) the spinners would not blanket the surface until 10:30 or even 11 in the morning. Why is that? I'd like to say that after astute observation I was able to discover what the key is for when the spinner fall commences. That would be false. What I did learn, via the old paper version of the Orvis News, is that tricos begin to fall when the air temperature hits 68 degrees. This was relayed to the late Leigh Perkins from Jim McLennan, a fly shop proprietor and guide on the Bow River out in Calgary, Canada.

I will not go so far as to say that 68 degrees is a hard and fast rule but it is certainly a solid rule of thumb. I have casually headed to the river when the air temperature is 64 or 65 degrees and found not only swarms of flies but also rising fish. I think that the rate at which the morning is warming is also a factor. If the day is warming rapidly then the flies will begin to fall before it reaches 68 but if the day stays cool later into the morning the 68 degree mark takes longer to occur. It is on these days that the 68 degree mark seems most important. And in late August and into September there are some day when 68 isn't even achieved. At such times the flies will linger and then finally fall late in the morning or even early afternoon.

Once the spinner fall commences, it can be viewed as a two stage event. With their mating duties completed, the black-bodied males will fall spent to the water en-masse. Fish begin to gobble these diminutive little specs as soon as they begin to drift past their feeding stations.

The second stage of the spinner fall is when the females, having waited a short period for their dark green eggs to ripen, begin to drop to the water to deposit the eggs and then die. The females have a creamy white body and black thorax. Some anglers will say that there is no need to make the distinction between the male and female, I disagree. While I do not view trout as being intellectually gifted, they do know what they see day after day. There is enough of a difference between the two to at least be prepared to have patterns for both just in case there is a particularly fussy trout.

As was hinted at earlier, there is also a cruel twist to this activity. During late August, swarms of tiny flying ants often mix in with the spent tricos and drift helplessly on the streams surface. Trout that have been feeding on the little mayfly spinners day after day for weeks will suddenly have eyes only for the tiny ants, which have black bodies similar to the tricos but have wings that lay horizontal rather than perpendicular to the body. The ants are very small indeed, with a # 24 hook being as large as one wants to go. By switching from a trico, with its broadly splayed wings, to an ant, with a flat or slightly upright wing, a few more fish will be brought to hand.

When the spinner fall has ended (the average fall lasts from an hour to 90 minutes) the surface will go dead and anglers just entering the river will not know that the best dry fly fishing of the day has already passed.

In the next installment we will cover various tactics for fishing this wonderful and wonderfully complex hatch and spinner fall. In the meantime, if you are heading out to fish, please have your thermometer handy and check water temperatures. Folks are encouraged to stop fishing at 68 degrees.