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Beetle Patterns for Summer Trout

When matching the hatch doesn't work, a beetle pattern may be your pinch hitter. Regardless of the season, a box of beetles should be in your fishing vest.

Beetle Patterns for Summer Trout

In the minds of the fly-fishing majority, beetles are typically considered a food source with a short seasonal availability. (Bonnie Harrop photo)

The idea of a magic fly is as old as fly fishing. And it is a safe guess that most of those who pursue the sport would be delighted to exchange the complexity of fly selection for a single pattern that would tempt trout to the surface in all situations.

While it is said that any fly will catch fish if it is fished long enough, we learn early that success hinges primarily on our ability to identify and match insects that have captured the attention of the trout at that particular moment. In the best habitat, it is typically mayflies, caddis, or another aquatic organism that induces the highest level of interest.

For dedicated dry-fly enthusiasts, hatches of aquatic insects are complicated, ever-changing situations addressed by vests heavily laden with fly boxes. As a willing member of this obsessive group, I always try to have the right fly at any given time on the wonderful and diverse waters near my home not far from Yellowstone.

At the expense of a frequently aching back, the 15 or more fly boxes I carry on most days do an acceptable job of handling what I might encounter in more than 100 days of fishing each year. For the most part, my flies are organized into specific replications of individual aquatic insects in their respective stages. And though they number in the hundreds, I carry no fly that is without basis for its presence in my vest. The makeup of my selections may change as better patterns evolve, but the volume of imitations remains constant. While some people view this as excessive, I consider the rewards of a heavy vest to be well worth the discomfort, which always vanishes when I am playing a big trout.

With familiar and quality water only minutes away, I usually plan my fishing time to coincide with the appearance of predictable hatches. But on a river like the Henry's Fork, you learn to expect the unexpected, and most days produce surprises of some kind.

Despite having a multitude of proven patterns close at hand, I find there are many times when my best efforts at fooling a particular trout are met with complete disdain. Most frustrating are those times when the trout's objective is clearly identifiable, and everything, from the cast to the choice of fly pattern, seems perfect.

Finding yourself in a heated engagement that may last up to an hour can be a casting marathon with numerous fly changes. Surrender is not an option when the trout is especially large, or when pride comes into play, but success in this situation can sometimes be achieved by an alternative plan that falls outside common logic.

"B" for Beetles

In my inside vest pocket, I carry a relatively small fly box marked "Plan B." Though humble in comparison to its more sophisticated companions, this assortment of flies often provides unconventional solutions to otherwise hopeless situations.

In the minds of the fly-fishing majority, beetles are purely terrestrial enticements to trout. Grouped with other land-based insects such as hoppers and ants, they are typically considered a food source with a short seasonal availability.

Beetles at high elevations in the Rocky Mountains generally attain adulthood in the warmer months of mid- to late summer. At the driest time of year, the mobile adults seek habitats close to water, where the vegetation remains lush until all begins to wither with the frost of autumn.

During this period of low water levels and decreased aquatic insect activity, beetles are at their peak. They are active and available along the edges of streams that flow through open terrain. 

Wind, rain, and other influences—such as grazing livestock—sometimes bring sizable numbers of these delicacies into the water where trout quickly seize upon the easy meals. Fishing a beetle imitation along shaded edges where streamside vegetation is present helps to fill quiet times when insect activity is sparse. Opportunistic trout take up residence in these areas and are constantly on the lookout for food items dropping to the water from above. 


Helpless in this condition, the beetles float low on the water and do not induce aggressive rises. A gentle sipping motion may be the only indication of a trout's presence, and this subtle feeding activity is easily missed.

Beetles are winged insects, and can fly to locations away from the streambanks, which means that beetle imitations sometimes work for midstream trout as well.

Random risers—when no particular hatch is underway—can be receptive targets for a drag-free beetle imitation. Trout recognize this food form, and the rise to a beetle in this situation is mostly confident—even energetic, if the trout is moving some distance to collect the morsel.  

Larger beetle patterns can also raise the excitement level, resulting in enthusiastic and showy takes. Modern beetle designs made of buoyant foam and lively rubber legs are especially known to evoke this response.

rainbow trout, beetle fly
Large trout often resist the most exacting mayfly and caddis imitations, and then crush a foam beetle with rubber legs. (Bonnie Harrop photo)

Although detached from common practice, it is possible in the proper time frame and location to fish a beetle exclusively with acceptable results. With no rules to the contrary, anyone is free to simplify their fishing by ignoring the complexity of trout behavior. I know plenty of Henry's Fork regulars who fish only a beetle pattern until they are completely satisfied that it will not get the job done.

Most anglers, however, when fishing to a trout that is seriously involved in feeding, base their initial fly selection on what they observe on the water. There are many times when beetles are the dominant food source, and an appropriate imitation is the best choice. This is often the case on breezy summer days when substantial numbers of beetles blow onto the water. I have never witnessed an occasion when the volume of these insects was adequate to create a feeding frenzy, but I do recall times when a beetle was the top-producing fly of the day. 

It is difficult for me to contemplate beetles without recalling Chuck Gash. He was elderly when I met him in the 1980s, and through most of the summer, he made an almost daily hike of more than a mile into the Harriman Ranch stretch on the Henry's Fork.

We never became closely acquainted, but I was impressed by the deliberate pace at which he fished, and his obvious love of the river. I watched his patient approach and the simple downstream presentation he seemed to always prefer, but we talked only in passing along the worn trail along the river's edge. On most days, his catch seldom seemed impressive, but he usually took a fish or two, which seemed to satisfy him.

Many Henry's Fork regulars believed that Gash always fished a simple black deer-hair beetle, regardless of what was actually on the water. He thought that, given a choice, a trout would always select a beetle over anything else that might be available.

Though this theory has never been completely proven to my satisfaction, there is definitely something special in the way trout respond to beetles. And like others who knew him, I credit Gash for creating greater awareness of this behavior. I carry and fish more beetles since I met him along the river.

Imitation Intelligence

On spring creeksand slow-moving meadow water, a trout's fondness for beetles does not reduce the need for careful presentation. My standard setup is usually a long leader of 12 or more feet with a tippet averaging about 6X.

A size 14 or smaller beetle pattern does not generally require a major leader adjustment when you're switching from a delicate mayfly or caddis imitation. I especially like CDC for its lightness, and use it almost exclusively for beetle patterns I fish in the surface film. The soft CDC fibers move subtly with the current, or from a gentle rod-tip twitch. Beetles float drag-free but occasionally wriggle their legs, and CDC mimics this minuscule motion beautifully.

Brown CDC Beetle

beetle fly recipe pattern, Rene Harrop
Brown CDC Beetle. (David J. Siegfried photo)

HOOK: #12-20 Tiemco 206BL.
THREAD: Rusty 8/0.
BODY: Pheasant tail fibers.
LEGS: Reddish-brown CDC fibers.
SHELLBACK: Two to four black CDC feathers, cupped over the body

Although brown and olive are also included, black beetle patterns dominate my fly box. Iridescence is a key feature of many beetles, which explains why peacock herl figures prominently in some of my most effective patterns. Ringneck pheasant-tail fibers, either natural or dyed, can also yield impressive results. For flies larger than size 12, I use dyed elk hair instead of CDC, although sadly this comes at the cost of extra weight and a tendency to become waterlogged. 

Rene Harrop, Henry's Fork, rainbow trout, beetle fly
Author René Harrop prefers small—#14 and smaller—CDC beetle imitations for shallow, flat water. (Bonnie Harrop photo)

Far from an advocate of closed-cell foam, I concede its advantages in larger beetle patterns, up to size 4. Although infrequently encountered in big numbers, beetles this large do exist, and no hungry trout will ignore a food item this size particularly when it is struggling on the surface.

Big foam bugs with rubber legs are favorite patterns of drift-boat guides floating in medium to fast water. Fished tightly along the banks, or in other logical holding water, these virtually unsinkable flies do not require much finesse when compared to conventional beetles. A fly alighting heavily on the water is not usually a problem because a crash landing often announces the arrival of a natural beetle. Ordinarily the kiss of death, drag can be a positive when it activates the lively rubber legs, and can generate savage responses from beneath.

Big Foam Beetle

beetle fly recipe pattern, Rene Harrop
Big Foam. (David J. Siegfried photo)

HOOK: #4-12 Tiemco 5212.
THREAD: Olive 3/0.
BODY: Peacock herl.
SHELLBACK: Green closed-cell foam.
LEGS: Gray and black rubber legs

Big trout in slow, clear, and relatively shallow water show zero patience for clumsy presentations or oversized or overdressed beetles. A longer, more refined cast is often required, and the flies must be more realistic.

Extremely large beetles are the exception to what the trout commonly see on the water. Smaller sizes are invariably more numerous, and therefore more familiar to trout.

Beetle Boxing

A box of beetles stays in my vest regardless of the season. Its contents are based upon observation, without regard to the origin of the naturals they represent. A beetle pattern comes into play when I observe naturals on the water, and I try to match what I am seeing at that time. There are times, however, when a trout's love for beetles is incorporated into a different strategy. 

Prowling upstream along the banks of a clear trout stream has become my practice during the quiet times between hatches. Watching for big resting trout outside the main flow can be productive when other anglers have given up for the day, with the added advantage of having a lot of water to myself. 

The real challenge is to spot the fish from afar to prevent it from being spooked by your casting. Entering the water can be an option if it is necessary to lower your profile, but this often comes at the risk of alerting or losing sight of the trout.

When practical, I prefer to kneel on the bank while keeping the objective in constant view. A long, fine leader minimizes the likelihood of the line or its shadow bringing a premature end to the game. 

A cast made from downstream must be gentle and accurate because the fly and leader must travel over and beyond the fish, and it is difficult to manipulate the drift once the fly is on the water.

When not actively feeding, a trout may require more time than usual to recognize a floating food item, and it is impossible to predict its response. At times, a startling rush to the surface occurs the instant the fly comes into view, but a trout can also ponder the decision well beyond the time when the fly passes overhead. I have watched trout turn and follow the fly 6 feet or more likely sensing that a beetle is not about to escape—and then take the fly going downstream.

Black CDC Beetle

beetle fly recipe pattern, Rene Harrop
Black CDC Beetle pattern. (David J. Siegfried photo)

HOOK: #8-14 Tiemco 100BL.
THREAD: Black 8/0.
BODY: Peacock herl.
SHELLBACK: Black elk hair.
LEGS: Black elk hair 

My policy when fishing beetles in this situation is to drop the fly at least 4 feet above the trout, and to delay the pickup until the fly has drifted 8 to 10 feet below. In my experience, three or four good drifts without a response requires a different fly. A subsurface nymph is the most logical alternative when a visible trout ignores a beetle.

Perhaps the strongest evidence of a trout's weakness for beetles is displayed when most anglers would not think of trying one. And while it's far from foolproof, more than one highly resistant trout has fallen to a tactic I refer to as Plan B. 

Nothing in fly fishing is more enthralling than a one-on-one showdown with an exceptional fish. I have spent countless hours locked on a single trout that defies my best efforts, both physical and intellectual. I love the challenge of making not one but many perfect casts, and the mysteries that can accompany the selection of the right fly.

Mayflies such as the notoriously complex Pale Morning Duns typically create this puzzle, and I relish the times when everything comes together in the right way. Personal pride and respect for my adversary usually prevent me from finding a way to short-circuit the hatch matching.

For someone who treasures the magic of a hatch, fishing a beetle at such a time is the equivalent of surrender.

On a river like the Henry's Fork, you become accustomed to disrespectful treatment from big, savvy trout. To become a sore loser is never considered a mark of strong character, but a man can take only so much. Eventually you need to come out on top, and more than one trout has submitted to a black beetle fished solely as an act of utter desperation.

Although highly prized by trout, beetles do not represent a substitute for solid knowledge of other food sources, and simply fishing a beetle imitation will not compensate for poor physical skills such as casting and presentation. In general, a beetle will be rejected at least as often as it is accepted, even with perfect presentation. Through a significant portion of the season, however, fishing a beetle can make as much sense as anything, and failing to acknowledge this fortunate reality is an avoidable mistake.

René Harrop is the author of Learning from the Water (Stackpole Books, 2010), and runs his own fly-tying operation, House of Harrop, from his home on the banks of the Henry's Fork.

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