Bob Boese, Louisiana

March 16th, 2009

Flies for Largemouth Bass
By Bob Boese, Louisiana

A warm spring evening marked the beginning of daylight savings time, as the flock of Mallard ducklings started life, six brown balls of fluff, closely huddled by their mother on the rippled surface of the lake. A week before, two other eggs had been taken by a water moccasin, which now lay on the bank and displayed the effects of a 3" load of #6 shot from a 12 gauge on perfectly good hat band material. Small pads of moss floated whichever way the fickle wind decided and the ducklings nibbled at the edges of the vegetation while mom dove occasionally for a submerged snack. Hoppers and dragon flies flittered through the tops of long grasses and bluegills splashed against the sloped green bank. Farther down the shoreline, a blue heron stood on one leg among bullrushes, very Audubon-esque, surveying the olive waters for dinner. The tiny flotilla of ducks moved along the shallows, one never more than a wing's reach from the other. Several large bluegill fell prey to a small yellow popper and, once released, hurried back to their newly formed beds. A full moon rose with Mars nearby and all was tranquil and serene.

First light came with a sprinkling of fog and the morning's symphony. Waters rippled from splashes of bluegill, aggressive and noisy as they snatched grasshoppers, real and artificial, with gusto. The sound of large mower was the overture for a flock of egrets to tiptoe through newly cut grasses while squirrels chittered in the tops of heavily laden pecan trees. Chickadees, mockingbirds and morning doves traded songs and, across the lake, the Mallard hen swam with five ducklings close by. Bluegills smacked after a pencil popper. An hour later the ducks passed again, the hen and four ducklings. Two days later, the call of dusk again brought fishing interest to the lake. Along the bank a Mallard hen and one chick swam. The fly fisherman's solemn look and small pang of sorrow for the disappearance of five cute little balls of fluff was real enough, but it was quickly erased by a wry smile.

Bream don't eat ducks.

In an ecosystem with alligators, gar and pike, largemouth bass still manage to fight for the top of the food chain. A bass' diet doesn't distinguish much by size or species, and insects face the same danger as fish, or frogs, or crawfish, or mice or ducks. A bass eats what is convenient, consequently, a wide variety of fly pattern strategies may be used in fly fishing for largemouth.

FINDING THEM: The bottom line to all of the information in this paragraph is that fly fishing for bass is most successful (1) in the shallows (2) during the spring and fall. There are good reasons for this. Not all of any lake has identical scientific properties and conditions almost always differ from one area to another. Bass follow optimal conditions around a lake. Many variables are involved, most importantly: pH, Oxygen (O2), and temperature. The pH is a measure of acidity or alkalinity. The pH scale runs from 0 to 14, with 7 considered neutral; anything lower than 7 is acidic and anything higher than 7 is alkaline (or basic). Bass have blood that is slightly alkaline (7.6), but can survive in water with a pH ranging from 6.7 to 9.6. At the same time a bass can survive oxygen levels from 5 to 13 parts per million (ppm) and that is where they will be. Bass are cold blooded, which means that they reflect the temperature of their surroundings and they rely on their environment to provide comfortable conditions. Weather extremes reduce O2 levels, making bass lethargic, they become practically comatose below 50 degrees and similarly inactive above 90 degrees. Largemouth bass prefer warm (not hot) water and spawning begins around 60-70 degrees. Bass thrive in 80 degrees (adult) to 84 degrees (juvenile). In these waters O2 is plentiful and bass are aggressive. All of which just goes to prove that bass are not everywhere in a lake, and even if you know where they are, they may not stay at that location. Because bass are sensitive to these variables, possibly as much as 50-60 percent of your favorite lake is unsuitable as bass habitat at any given time —which may be why you never caught one in that "fishy" looking spot. During the spawn they are generally found in shallow flats. As the spawn winds down, bass move into deep water, where they spend the dog days of summer. For many lakes, deep means deeper than a fly rod can fish. Both summer and winter bass usually hover at the thermocline (where water temperature changes subsurface) because it provides them with the best temperature for more oxygen, but there are a few bass which will always remain in the shallow flats areas (mostly juveniles) and around vegetation. Fishermen mistakenly think weeds and vegetation are simply ambush spots (which they are), but the truth is also that vegetation on the surface can absorb heat and transmit it to the water, consequently the shade under weeds may actually be warmer than surrounding waters and in cool weather is inviting to bass for that reason. On hotter days, water under vegetation may be unsuitably hot. Consequently, finding fly rod accessible bass is a matter of anticipating shallow water temperatures. When summer water temperatures cool, bass return to shallow-waters where they will feed before moving again to the deep water for the winter and when winter temperatures abate they return to the warm shallows to spawn. For this reason, the fly fisherman should concentrate on spring and fall.

WHAT BASS EAT. For the fly fisherman, the critical components of a bass' diet are fish, insects, crawfish, and occasional special meals such as frogs, lizards, ducks and mice. Bass like big meals, and, given the choice, will opt for a large victim, even one that barely fits in its mouth. Essentially, no fly is too big. Consider that the largest fly it is feasible to cast on a 6-7 weight outfit will be small compared to something like a crankbait or buzzbait. On a sunny day at the local airport I stood on a small bridge and watched several dozen bream and a couple of healthy bass swim through the shadows. There were the bass, surrounded by easy to catch meals in a confined space, and they did little more than nudge the bream aside as they swam through. Until that time I considered bass a killing machine, gorging constantly. I have come to learn that bass use two clues to feed: (1) when they are hungry, and (2) when environmental conditions tell them to. If either of these is missing, they don't feed and bass conserve energy and prefer to move as little a possible to get a meal. As the time passed and I waited on the bridge, one of the larger hand-sized bream swam in front of and slightly above one of the bass. With a movement so quick I wasn't sure of what I saw, the bass snapped it's head up and to the side and the bream disappeared — presumably in the bass. It was a big meal —a bluegill in the wrong place, wrong time. [Bass eat plenty of sunfish, but, given the choice, will eat more streamlined easily swallowed fish —shad, small bass —instead. However, if a bass has never seen a shad, it will feed first on a familiar prey.]

For the fly fisherman there are four main groups of flies that will work to catch bass, but normally not all at the same time and sometimes none work at all: (1) Fish replicas —these would include minnow imitations (metalic wooly worms, clousers and deceivers); (2) Insects —this can include anything from a #14 nymph (on which I have caught a 5 pounder) to large beetles, hoppers and dragonflies; (3) Crawfish, and (4) large amphibians, water foul and small mammals. FLY SIZE: Generally, if all other things are equal, larger is better. In certain waterbodies, where smaller minnows and insects are prevalent and easy to catch (and other choices are few), bass will feed on small offerings if they are presented close to the bass and if the bass is hungry (since any fly presented to a bass that is not hungry is doomed to fail). Bass migrate around a water body for better environmental conditions, but do not like dining on the run, especially for a small snack. Bass have spines (cartilaginous projections which point forward and inward from the gill arches) in their throat called gill rakers. These hold food in the bass while water is passed over the gills. A bass will choose large meals whenever possible. Larger prey is easier to hold in the gill rakers (small prey may actually be flushed out). Bass are not smart, but they have good natural instincts. While these fail on occasion, usually a bass will normally not eat something to small for the gill rakers or big enough to kill the bass (by suffocation) in the effort to eat dinner. Research indicates that if a target prey is up to half the size of a bass it is fair game. By focusing on larger meals, the bass can conserve the amount of energy used for hunting and gain energy from eating.

WHAT BASS SEE —BASS VISION AND FLY COLOR: Because of their field of vision, bass predominantly attack upwards. Like other predator fish species, bass have good vision —180 degrees for each eye. This allows them binocular vision in front and up where the 180 degrees of the eyes overlap. There is a small blind spot directly between the eyes and a large one from the side fins back and under the belly. In other respects, bass vision is complicated to explain. They can focus well at various distances. Because their lenses are spherical, this enables them to see underwater because there is what is called a higher refractive index to help them focus, which they do by moving the lens in and out. They can also see under various light conditions. A basses lens bulges through the iris so their pupils do not dilate or contract but they have a special pigment that shields the eye from bright light and structures which amplify the incoming light allowing for good vision in low visibility conditions. Consequently, it can be assumed that bass get a pretty good look at their prey.

Although there is no agreement about what color to use, there is not a lot of controversy about a bass' color vision. Bass can see in color. Some of the wise guys say it is best to mimic the color of the prey the fly represents (green frogs, blue dragonflies, brown crickets, etc.). Others say that cool colors (blue, green) retain their color better with depth of the water and should always be used when fishing deeper. Still others say that florescent colors are even better than regular cool colors at retaining the original color. What is known by science is that the retina of a bass' eye contains two types of cells: rods (for night vision) which don't see color but show light intensity, and cones (for day vision) which can distinguish colors. In clear water on sunny days, warm colors disappear in this order as you get deeper (red then orange then yellow) but unless you are trying to get a fly down to 15 feet or more it doesn't matter. (In cloudy water or on overcast days, warm colors fade to dark brown or black much shallower.) But, what bass notice more than color is contrast. This means than a surface bait can be practically any color but should have contrast as well. Experience shows that contrast is frequently the most important factor. An orange spider fly with white legs is not a color usually seen in nature, but stands out well to bass. Red with white are a standard combination that nature ignores, and, although black and yellow is bee-ish, it probably works because the high contrast. Remember that a bass sees only the bottom and some of the side of your fly. Meticulously decorating the top of the fly is for your benefit, not the fish's. But, this has one good consequence in that adding a Chernobyl-style extra layer of foam to help flotation won't discourage bass from striking.

MASK HUMAN SCENTS: The sense of smell (chemoreception) is very well developed in bass, which rely upon this sense to detect prey, to avoid harmful PH conditions or harmful chemicals, and to find suitable oxygen content. Largemouth bass have paired nostrils (nares) on each side of their head between the eyes and upper lip. The olfactory rosette (epithelium), consists of complex folds that line the nostrils. Within the epithelium, odor activates olfactory receptor nerve cells. Older bass have a larger number of olfactory folds with a larger diameter. Consequently, older bass can smell better and can detect odors 20-30 feet away that are equivalent to a few parts per million in the water. Using fish attractants and scents is not commonly associated with fly fishing, but there are reasons to consider making limited use of them. Primarily, attractants mask human scents that are repulsive to bass. A fly that smells like human sweat, sunscreen, cologne, tobacco, beer, gasoline or head cement may not be effective for just that reason. But while spraying a fly with attractant seems sacrilegious, a simple solution is to apply fish attractant to your hands then handle the fly. The downside is that fish attractant is usually oily, making many fishing tasks more difficult. [Make-your-own scent options usually involve baby oil and anise, or WD40.] Many attractants use some form of anise (licorice) as the primary masking agent. Non-oily anise is available in liquid form on food seasoning aisles and a drop rubbed on your fingers will usually suffice to mask offensive smells. Picking up and tying on the fly should transfer enough anise to the fly to do the job without affecting performance.

DELIVERING THE FLY: Because it's important, it bears repeating: bass don't move around unless they have to because of environmental conditions or instinct (e.g. spawning). Usually, catching bass means working a fly near the bass. Anywhere in the line of vision has potential, but six inches takes less work on the bass' part than six feet. As opposed to many species, a delicate delivery is not required. Mice falling into the water panic, baby ducks swimming by have quickly paddling webbed feet, frogs have an elongated moving profile as they swim, an injured fish will thrash or jerk or move erratically, and all of these make ripples, vibrations or splashes. A fly splashing onto the water signals to a bass that something has fallen in, not that something is out to get her. Remember that fishing birds are either greatly patient and statuesque, or dive bombers that only splash an instant before eating. If a bass hears a splash and has not been eaten, it considers the source food. Bass have ears located behind the gill plate together with a lateral line system. A bass' ears are divided into an upper section (that gives the bass its sense of balance) and a lower section that translates vibrations felt by the bones and tissues surrounding the ear into sound. Most important, however, is the lateral line system. Within the lateral line are sensory structures (neuromasts) and each neuromast contains hairs covered by a gelatinous cupula —which is the component that extends into the lateral line canal where it is exposed to water. Vibration in the water causes the cupulae and enclosed hairs to bend allowing a bass to precisely determine the direction of the vibration source. In this way bass can identify the presence of prey (perhaps even distinguish species) at considerable distance.

WORKING THE FLY: In nature, creatures do not perform synchronized swimming. Movements of prey are often erratic, sometimes panicked, and frequently unpredictable. For this reason, the movement of a fly should not be consistent or unchanging. It is easy to fall into a lazy cycle where every movement of a single retrieve is identical and every retrieve is like every other. Stupid fish can be caught this way, but smart fish live longer and get bigger. Bass baits should make noise and resemble something scared or hurt. Mice have tiny legs not made for swimming. A mouse in the water is practically helpless and knows it, and shows it with a flurry of movement toward the nearest cover. Hence, a mouse fly should be retrieved with a lot of racket but not too rapidly and toward cover, not open water. Large bugs freak when they hit the water, then are exhausted quickly, then freak again. This is best reflected in the strip-pause-strip-pause retrieve. Frogs are used to the water but don't like spending time in open waters. The best retrieve for a frog fly is strip-strip-strip all the way and fairly fast. Minnows are most appealing to bass when they are injured. Minnow replicas should get a strip-strip-pause type of approach causing the bait to move through the water in spurts then fall as an injured fish might. Expect the strike on the fall. Smaller insect replicas should be retrieved very slowly unless the bait is a dragonfly nymph (which jets through the water in short spurts). Small bugs do not move fast through the water even with a lot of effort and generally go where any movement of the water sends them. If it happens to bring them near a hungry bass, well, not all luck is good.

CRAWFISH: Crawfish get their own heading here because there are almost no hard and fast rules for fishing crawfish flies. Yes, biologists have found that crawfish (particularly young crawfish) are a common food for bass. Actually, some studies indicate that where crawfish are prevalent, they may compose 75 percent of a bass' diet. Why? Because when they are around there are a lot of them, they are high in protein (instinct tells bass it is good for them) and they are easy to catch (bass don't have to spend energy finding them). The average lifespan for crawfish is one to two years and they produce young in every season but winter (sometimes then in warm winters). With thousands of small crawfish readily available, bass will still take the big meal large crawfish if it is available. (Consider the effectiveness of the "jig and pig" traditional bait, a huge crawfish replica offering that consistently takes bass.) Consequently, the fly fisherman is initially faced with a critical choice: replicate the smaller more prevalent young crawfish, or the big meal older crawfish. In large part, the decision may be dictated by the fisherman's choice of equipment. Large heavy crawfish flies take larger rods.

The next decision is color. Louisiana has about 29 varieties of crawfish and few of them are identical. Young crawfish can vary from practically clear to dark olive, while mature crawfish vary from light pink with a white underbelly to brown/black with orange or blue highlights. Choosing the right color may be the most critical factor because if the fly doesn't look like the bass' forage, it will likely be ignored. To make things more complicated, crawfish can change colors seasonally or depending on their surroundings. In a perfect world the fly fisherman would have the opportunity to catch a few crawfish the day before and check to color. Since chances of this happening are usually nil, the option is to bring many color variations of your favorite crawfish pattern. You can always hang a piece of bologna over the side of the boat or dock as you fish and see if a crawfish is interested, otherwise carry at least a grey/green, red/orange and black/brown selection. A relatively easy pattern that looks okay in the water can be found at (see "crawfish"), although I would recommend using ziplock bag material (cheap) in lieu of expensive and not readily available thin skin.

The third decision is how to fish the crawfish fly. A threatened crawfish will infrequently try to face down a bass with its pinchers out, but more likely will back away slowly (very common) then take off in a short fast spurt. Sometimes the spurt comes first so the fly must be fished with no consistency or repeated movements. However, it must be fished on the bottom. Swimming crawfish have no cover to hide in, so they don't if bass are around. ~ Bob

About Bob:

Robert Lamar Boese has fly fished for five decades. He is an environmental negotiator, attorney and educator who has provided environmental legal services for more than thirty-three years including active duty with the U.S. Coast Guard and Department of Justice. He is a well known fly tyer with several unique patterns to his credit. He has developed and authored federal and state regulatory programs encompassing a broad spectrum of environmental disciplines, has litigated environmental matters at all levels of the federal and state court systems, and is a qualified expert for testimony in environmental law. He has authored over 60 published text chapters, comments or articles on environmental matters, is a member of the Colorado, District of Columbia and Louisiana Bar Associations, and is a certified mediator. In addition to his legal practice, Mr. Boese has been a high school teacher, an associate professor of Environmental Law and Public Health, has authored numerous fiction and sports publications, and is a softball coach and nationally certified volleyball referee. He is the president of the Acadiana Fly Rodders in Lafayette, Louisiana and editor of Acadiana on the Fly. He has been married for thirty years and is the father of two fly fishing girls (25 and 21). For additional information contact: Boese Environmental Law, 103 Riviera Court, Broussard, LA 70518 or call 337.856.7890 or email

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