Mayfly Bream Frenzy

Look for fast, frenzied action during a mayfly hatch.

John N. Felsher | May 10, 2018

One hot June afternoon, we struggled to find fish in a sweltering backwater off a major river—until we noticed some activity up ahead.

A sight any fly fisherman longs to see, millions of mayflies covered bushes growing along a cypress-lined stretch of shoreline about 10 yards long. As if a million piranhas attacked a bleeding capybara, water boiled in the bayou below the bushes with fish annihilating anything that touched the water.

My fishing partner and I immediately whipped out our fly rods and dropped cork poppers into the ruckus. Unfortunately, a roaring wind made stopping to fish the honey hole impossible without an anchor or trolling motor. In addition, the ancient 12-foot aluminum boat leaked so badly that we had to bail it with a gallon milk jug about every 30 minutes just to stay afloat.

Fortunately, the wind blew parallel to the bank where we wanted to fish. We formulated a plan. I cranked up the also ancient 6-horsepower outboard and headed upwind while my buddy bailed the boat. We stopped far enough upwind so that we could get our fly gear ready for a quick drift past.

As we shot past the strike zone, we each furiously made a cast or two, hoping we didn’t snag on anything. If the bug hit the honey hole, a big bluegill or other fish instantly blasted it. If the bug missed the sweet spot, nothing happened.

About the time we went past the honey hole, the boat needed bailing again. We bailed the boat dry, or at least as dry as we could for something that resembled a noodle strainer, and hoped the engine would crank. Fortunately, it did. We ran the outboard up past the bug-laden bushes for another drift, repeating this effort many times that afternoon until we grew tired of catching fish—and bailing.

Also called willowflies or shadflies, mayflies spend most of

Sometimes mayfly hatches can be of Biblical proportion. These swarms can get so massive that they are picked up on weather radar. These bugs create a feeding frenzy for bream and other fish species.

their lives living underwater as nymphs. Some of the

more than 3,000 mayflies species in the world live several years, but most only live a few months or up to a year. However, when they emerge as winged adults, they can create a feeding frenzy that attracts every fish in an area. Anyone who happens upon a hatch could load a boat with bream in a short time.

“Mayflies are found all over the Southeast and throughout the world,” advised Dr. Marianne Shockley, a professor of entomology at the University of Georgia. “The lifecycle of a mayfly can range from one to two years, up to three to four years depending upon the species. Most of that is under water. Mayflies are generally associated with flowing environments like rivers, creeks and other streams, so they don’t do so well in stagnant ponds.”

As a nymph, a mayfly looks somewhat like an elongated and flattened cricket. In their aquatic form, the bugs live under rocks, logs, decaying vegetation or silt. Many fish, crustaceans, carnivorous insect nymphs and other organisms eat the mayfly nymphs when they can find and catch them. Fly tiers often make creations that resemble these nymphs to attract bass, trout and panfish, but the real feasting erupts when swarms of insects sprout wings as adults and emerge from the water.

“Mayflies are semi-aquatic insects,” Shockley said. “They do all of their feeding in the water. Some mayfly nymphs are predators and eat other insect larvae. Some even eat other mayfly nymphs. Some graze on algae growing on rocks, plants or logs or eat detritus. Fish and other creatures eat the nymphs in the water, but when they are swimming around, they will not be concentrated or easy to find. They are usually under rocks or other objects for protection, but things like salamanders that can crawl around under things can access them.”

When ready, mayflies go through a transformation to become winged insects that somewhat resemble overgrown mosquitoes but cannot bite or sting people. In fact, they can’t even eat. In their final stage, they exist solely to fly around and mate in the air, lay eggs and then die. Mayflies belong to the insect order Ephemeroptera, which means, “lasting only a day.” Females typically lay between 400 and 3,000 eggs.

“Before they reach their adult stage, the flies go through different stages in which they shed their skins and grow before they develop their adult wings,” Shockley explained. “Then, they crawl up the leaves or debris and do their final molt into the adult stage outside of the water. As soon as they mate and lay eggs, their job here on earth is done.”

Hatches, technically just the bugs changing from aquatic nymphs into winged adults, generally occur on warm days in sluggish eddies or river backwaters where they can find calm water. During a mayfly hatch, millions, perhaps billions of individual animals can cover trees, automobiles—anything they can find. With little defense against fish, birds, reptiles and a multitude of other things that want to eat them, the flies must swarm in huge numbers to overwhelm predators so that some individuals survive long enough to mate, lay eggs and propagate the species.

“As a huge colony, adult mayflies all emerge at one time or in a very short time, usually between 12 and 24 hours,” Shockley said. “Mayfly hatchings commonly occur throughout Georgia. Because they do not feed as adults, they all need to be swarming and mating at the same time because if they miss it by just 12 hours, their fecundity is limited. Sometimes, mayflies get so thick after an emergence in some places that people have to push them off bridges with snowplows.”

Huge swarms can even appear on weather radar. In 2014, a mayfly hatch on the upper Mississippi River near La Crosse, Wis., reached an altitude of 2,500 feet. On radar, it looked like a significant rainstorm. In June 2015, a hatch along the Susquehanna River near Columbia, Pa., grew so thick that police had to close to bridge over the river to automobile traffic because the dense swarm created significant visibility problems for motorists. In addition, drivers could not see out of their windshields splattered with so many smashed bugs.

Different species hatch at different times. Even members of same species hatch periodically through the year. In Georgia, hatches might occur from late March into October with the peak lasting from May to July. After emerging from the water, the flies cling to branches, low bushes, reeds or whatever they can find to dry their new wings. Sometimes, so many bugs gather on small branches that they break them.

“Mayfly season in Georgia typically occurs from late spring to early summer,” Shockley detailed. “Sometimes, hatches can occur into early fall, depending upon the location and the weather. They won’t emerge if it becomes too hot or too cold. In most years, the mayfly season might stretch out to October.”

When bugs hatch, some inevitably fall onto the water surface. Breezes blow others into the water. All of them die after mating, and many of those insects also hit the water. When such huge amounts of free protein enter the food chain, it kicks off major feeding activity.

Steven Felsher shows off a bream he caught on a cork popping bug.

“Fish are very in tune when insects fall on top of the water,” Shockley advised. “They can certainly see the shadows of that emergence and the flies over the water. Insects are a prime food source for fish and good sources of protein for fish, birds and many other animals. When a mass hatch occurs, it’s just like opening a candy store for fish like trout and panfish. When they fall into the water, they become prime targets for everything that swims.”

Anglers can never know exactly when or where a major hatch might occur, but when one happens, word spreads quickly. Fishermen lucky enough to stumble upon a bug hatch in progress could find fast, incredible action. When flies hit the water, everything comes quickly to grab its share of the bounty. Anglers fishing a good hatch can usually catch bream after bream with anything they throw into the water.

For the most fun, fish a hatch with fly tackle. During a bug hatch, bluegills turn particularly aggressive and might smash anything hitting the water before their cousins can grab it. Pound for pound, or more appropriately ounce for ounce, nothing can outfight an enraged bull bluegill hooked on light fly tackle.

Flies that resemble floating insects might work best, but during a feeding frenzy, lure color or selection doesn’t matter as much as placement. Toss a temptation as close to the fly-laden bushes as possible without snagging. If it lands in the right spot, something will probably hit it. If the frenzy dies down, shake the bushes to make more flies fall into the water and reignite the activity.

Even when not in a fly gulping frenzy, bluegills and other panfish often blast floating popping bugs with vicious ferocity. The floating insect imitations made of cork or wood adorned with feathers and rubber “legs” come in many color combinations and make deadly topwater temptations all year long. Some foam or plastic temptations resemble crickets, grasshoppers or other creatures that bluegills love to eat. When feeding near the surface, their little mouths make distinctive snapping noises. Quite audible for considerable distances, these snaps allow anglers to zero in on feeding bream.

When not fishing a mayfly hatch, drop a popping bug as close as possible to shorelines, fallen trees, docks, stumps, lily pads, weed beds or similar cover. Let it rest on the surface a few moments until the ripples fade. Then, give it a small twitch or pop before pausing again for several seconds. Sometimes, bream want more dynamic action and sometimes they prefer it subtle. Frequently, bream bust popping bugs just sitting still on the surface. At times, a slow, steady pull across the surface attracts attention.

Fly-casters don’t need fancy equipment to catch bluegills. A 7.5- to 9-foot long ultralight to light-action fly rod works great. Floating fly line coupled with a 7- to 10-foot length of 6- to 10-lb. monofilament leader completes the package. Tie on a floating popper, and start catching fish. Hot colors for poppers include black, blue, white, green, yellow or a black and yellow “bumblebee” combination.

Near a good hatch, anglers can usually catch fish after fish with other techniques besides fly tackle. Hop small jigs over the bottom or run tiny crankbaits through the area. Many anglers love to throw Beetle Spins for big bream. Toss one to a good spot, let it sink and count. It sinks about one foot per second. After it hits bottom or the desired depth, slow-roll it just over the bottom. Anglers can also “buzz” spinners over the surface or “wake” them just beneath the surface in a steady retrieve.

Many anglers also fish Beetle Spins with a pop-and-drop method. Begin a slow retrieve and occasionally pause to let the bait sink. The spinner rotates as the lure sinks, creating flash. After it sinks a foot or two, begin reeling again. The retrieval speed determines the depth the lure will run.

Bass anglers can also benefit from a mayfly hatch. Some bass eat the small bugs, but larger bass gather under a hatch to wait for an opportunity to snatch a big bream focused intently upon stuffing itself with flies. For bass under insect swarms, fish crankbaits or spinnerbaits in bream colors.

A fly hatch can erupt on any freshwater system in Georgia at any time. Look for insects clinging to low branches over the water or surface disruptions. No one can predict when or where a major hatch might erupt, but finding such an event could turn any humdrum day into a memorable experience and put a many delicious panfish in the boat quickly for anyone carrying the right equipment and ready to take advantage of the situation.

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