The battle against flies is constant, but there are ways to reduce the numbers of these costly pests—without pesticides and toxic chemicals. Fly control tactics have changed a lot in the past several decades. After the advent of pesticides, the emphasis was on spraying the premises or use of chemicals on the animals themselves (pour-ons, back rubbers, insecticide ear tags, etc.) but now we realize that some flies are developing resistance to these chemicals, and we've also become more concerned with the environment. Use of pesticides can be harmful to beneficial insects as well as the ones we are trying to control.
Controlling Flies That Breed In Manure And Organic Matter -- In livestock operations, one of the biggest problems is filth flies that breed in rotting organic matter such as old bedding/manure, wasted hay, etc. Bill Clymer, PhD (entomologist at Amarillo, Texas and Senior Consultant for Spalding Laboratories designing fly control programs) says that the predominant fly in any geographic region is the house fly, and the second biggest pest is the stable fly. The latter is about the size of a house fly but a very aggressive biter, usually feeding on the legs and lower parts of the body. Cattle being attacked by large numbers of stable flies are restless and don't eat well, often grouping together tightly to try to avoid these flies.
“Stable flies don't breed in straight cow manure like they will in horse manure. They prefer any kind of decaying matter that's high in plant waste such as wet hay or old bedding. Texas A&M did a study two years ago and found that if you don't clean up the areas where you feed big bales in feeders, this makes ideal breeding ground for stable flies,” says Clymer. The researchers estimated that the area around one big round feeder would produce more than a million stable flies.
“On my own operation we unroll big round bales in the pasture, but in the corral we put the bales in feeders. In the spring, one of the first things we do when it starts warming up is move the feeders and spread out the wasted hay with a front end loader, so it will dry out—or put it in a big pile so it will start heating. Otherwise this material will stay wet almost all summer and continually provide bedding sites for stable flies,” he says. You want it to dry out or heat it up. Properly composting material becomes too hot for the flies.
Hay and old round bales left on the ground are major sources of flies. Clymer's favorite piece of advice for controlling these flies is to follow three rules: sanitation, sanitation and sanitation. “If you do any one of these three things, you won't have nearly as many flies,” he quips.
Sometimes, however, no matter how well you clean up your farm, stable flies come in from neighboring areas. He recalls a place in southeastern Colorado that was having a serious problem. “It was the cleanest place I'd ever seen, regarding manure management, but on the southwest corner the stable flies were terrible. I couldn't find any breeding sites on the property so I started driving toward the southwest—the direction of prevailing winds,” he says.
About a mile away he saw a pole barn where alfalfa hay had been stored. “The hay had been taken out and all that was left was a thick mat of alfalfa leaves. A blowing rain earlier that season got that material wet. I dug into it with the toe of my boot and saw hundreds of stable fly larvae. We cleaned out that barn with a front end loader and scattered the litter around on the ground where it could dry, and within a day had eliminated the stable fly problem,” says Clymer.
You need to find the source of fly breeding and deal with it, if possible. Clean-up in the spring, and using a biological control like predator wasps can keep the fly population from building up by summer. The tiny parasitic wasps are sold commercially, and lay their eggs in manure and rotting organic material. Their hatching larvae feed on fly larvae and pupae in the manure. The wasps can be ordered from several different companies, and put out early in the fly season before the fly population becomes large, with more wasps put out periodically through the summer.
“If you can keep flies from getting ahead of you in the spring, you may not have to do as much to control them during the hottest part of summer,” explains Clymer. Heat and drying make it harder for fly larvae to survive. But if you get a big rain, this makes conditions more ideal again for awhile; about 10 days after the rain you will see a tremendous increase in emergence of house flies and stable flies.
“Most of my consulting clients, when I worked in feedlot areas (as a consultant for Fort Dodge), initiated a program where they tried to get rid of all breeding sites such as wet spots from leaking water troughs, and were cleaning the pens whenever there were not enough animals to keep them trampled (picking up the manure at least once a week), since under optimum conditions the flies will be breeding and hatching in 7 to 10 days,” says Clymer. Most of the feed yards also started using parasitic wasps to help control fly development.
“I've had the best results in fly control by using sanitation coupled with parasitic wasps. This won't have any effect on deer flies or horse flies (since they don't breed in manure) but can greatly reduce the numbers of house flies and stable flies,” he says.
Another biological control is use of Muscovy ducks—a breed of meat duck that spends its time on land (rather than water) eating insects. Some small farmers claim that four or five ducks per cow virtually eliminates a fly problem. According to Dennis French, DVM (Louisiana State University), in research trials, Muscovy ducks removed adult house flies 30 times faster than fly traps, fly paper rolls or bait cards. Ducks in cages with 100 flies took only 0.6 hours to remove 90 percent of the flies compared to 15.3 hours for the most effective commercial bait devices. “In other studies, the ducks lived for 12 weeks in pens with calves, without injury or any additional feed for the ducks. They ate about 25 house flies per 15 minute observation period when fly populations were low to moderate,” says French.
Biological control of horn flies (that breed in fresh cattle manure) includes use of dung beetles. These beetles live in fresh manure and carry it away in small brood balls or tunnel underneath the manure pat and bury it. The beetles' developing larvae consume the manure. Activity of the beetles disrupts the manure enough to eliminate or retard the development of fly larvae by about 90 percent. Native dung beetles are helpful (if they are not killed off by insecticides or deworming products that end up in the manure) but are not as efficient as some of the larger species that have been imported from Africa.
Fly Traps – There are a number of fly traps available today, and new ones being developed. Various types of traps have been created for different types of flies. Greg Johnson, entomologist at Montana State University, says that years ago he used panel traps for stable flies. “You can catch a lot of them with one of these traps—made with flexible plastic and a sticky covering on each of the panels. Sunlight is reflected off the panels and it attracts the flies,” he says.
Clymer says these traps were developed in Florida, looking at the type of light that attracts stable flies. “Researchers used white plastic panels around the perimeter of a property, to catch flies that are migrating in from somewhere else. You don't get all of them, but in the Florida study they got several hundred flies per day in these individual traps,” says Clymer.
Don't put any kind of fly trap that uses an odor or bait attractant by your back door. “The traps attract flies and some of the flies may go right into the house when the door is open,” says Clymer. You want the trap a ways from the house so the attracting odor will draw them away from your door and to the trap.
By contrast, a simple home-made fly trap using a tray or pan of water with a little dish-washing detergent added can be placed anywhere. A white or light colored tray or pan works best since the flies seem to come to it better. Any insects that land in it are drowned because the soap breaks the surface tension on the water and they immediately sink.
Dr. French says there are some relatively new horse fly/deer fly traps that are quite simple in design. “One is a black ball that attracts the flies. They go up underneath a canopy to get to it, and when they decide this isn't where they want to be they fly straight up and into a jar that captures them. A couple of my clients use these traps and report that they work quit well,” says French.
Another type of fly catcher, marketed by Bayer, is called Quikbayt, he says. “The active ingredient is imidicloprid. This is one of the better bait systems I've seen. Flies are attracted to it and caught. This system is used by some of the dairies; they put a thin layer of the bait material on a pie tin, and place the tins in several places in the barn and it reduces the fly population a lot. I think this system is more effective than sticky strips and stink bombs,” says French.
Devices that kill flies on contact (such as the fly electrocuters) kill some flies, but not all types. Lee Townsend, PhD, Extension Entomologist at University of Kentucky, says that house flies will go to these, but stable flies and horse flies typically do not. “Some of the mosquito magnets produce warmth and carbon dioxide and are attractive to a number of biting flies, but it's hard to say how what percent of the fly population they kill,” he says.
“In large open areas without many sources of blood meals for mosquitoes and blood sucking flies, a trap might be more useful than in an area where there's vegetation or buildings and a lot of competition for the flies' attention, or other things that would block out what's attractive about these traps. We've used some of these traps for mosquito studies and we do get other insects and flies caught in them, but you shouldn't rely on these to solve a fly problem,” says Townsend.
One of the most effective ways to control biting flies (especially horse flies and deer flies) is the Epps Biting Fly Trap™, invented by a cattleman in Oklahoma, Alan Epps. Epps runs 250 cattle and came up with this novel trap after being frustrated by the failure of other methods to control biting flies, especially horse flies. In summer his steers were covered with flies, dripping blood from the bites, and developed big welts all over their bodies. He'd tried common methods of fly control, including insecticides on the cattle, but nothing worked very well or for very long. It's especially difficult to control horse flies and deer flies because they breed in wet areas (where you can't use pesticides because of concern for the environment) and their breeding sites may be miles away from your farm or ranch.
Epps' trap is now made and marketed by Mark and Virginia Bonacquista (Horseline Products), a young farming couple in Henderson, Tennessee. “This is not a new product. It's been out since 1999, but it's new to us,” says Mark Bonacquista. Farnam was selling it before they took it over.
“Epps tinkered with different things ideas for three years and researched the natural habits of biting flies,” explains Bonacquista. Flies are attracted to the shape and silhouette of an animal, so Epps made a framework of wood to attract them. The frame has a large contrasting surface area, utilizing a dark portion and transparent panels to simulate air space above an animal and under its belly—the areas flies normally circle before landing on the animal to bite. When flies hit the transparent sheets they ricochet into trays of water below, and drown. Each tray holds 3.5 gallons of water.
In 1998 Epps presented the idea to Farnam. That company manufactured it until 2007 when they were bought out by Central Life Science, and closed their farm division. Every product in the farm division was discontinued, including the fly trap.
“We'd been using their fly trap five years with great success, and called to order more of the clear plastic sheets—the only things we'd ever had to replace on the traps. We loved those traps; we'd found out about them through our veterinarian. We'd come to the same point of frustration after using sprays, fly collars, rub-ons and feed throughs. Nothing seemed to work, especially for two of our horses. They were running through thickets and brush, cutting themselves up trying to get the flies off,” he says.
“When I called to order more sheets and found they were no longer available, we contacted Mr. Epps and signed a contract with him to manufacture the product ourselves and distribute it worldwide,” says Bonacquista. He and his wife took over the product last year and 2008 is their first full fly season, selling the traps.
“On our website we have a video that explains and shows it working. Farnam's entomologists claimed it would kill all the flies on 40 acres, but I'm not confident enough to make a statement that bold. It will definitely clear all biting flies from 20 acres, however,” he says. Biting flies (horse flies, deer flies, stable flies, black flies, mosquitoes, etc.) are attracted to large dark objects. “If you have a black horse and a light horse, or a black cow and a light colored cow, flies are more attracted to the dark one. They tend to fly around the animal two or three times before landing. The two plastic sheets are on a 45 degree angle with the trap,” he explains. The flies run into these sheets, thinking they're flying over the animal or around its legs.
“They hit the clear sheets, fall into the water, and drown. You add 8 drops of dishwashing soap to each tray, and the soap breaks the surface tension of the water so insects can't float on it; they are immediately wetted completely. They sink and drown quicker.” They can't float, swim or climb out.
“When we starting using our trap, within less than a month we'd reduced our fly problem. Research showed that a trap kills on average about one pound of biting flies every day,” says Bonacquista. The actual amount depends on the fly population.
“Each year, our fly population is less. Now we're only getting a pound of flies every week. When you start killing half a million biting flies, it starts to make a dent in the population because they can't reproduce as quickly.”
A research project at Cornell University and University of Florida will publish results in April. “One of the researchers told me our trap was 10 to 1 compared to any other trap they tried. They tested it for three years in upstate New York on dairy farms, looking at a non-chemical approach versus use of pesticides,” he says. The problem with pesticides is that they only work short term and some insects are developing resistance.
Fly predator wasps help control house flies and stable flies that lay eggs in manure, old hay or bedding. But they have no effect on horse flies and deer flies. The fly trap is more universal since it kills all biting flies.
“Alan Epps created this trap to trick them. It's black and produces a silhouette and gives off heat. It catches a lot of flies in the evening when the dark portion is still warm,” says Bonacquista. When air temperature cools, the black fly trap is warmer, and the fly thinks it's an animal. The fly can still see the light part, so that's where it flies. You can hear flies hitting the sheets—ping, ping, ping—and falling into the water traps.
The trap costs $295. “This is a one-time investment. I've talked with people who've had their traps since 1999 and they still work well. You just need to replace the clear plastic sheets every one to three years because they deteriorate, but those sheets only cost $8,” he says. This is inexpensive, compared with what you'd spend for sprays, repellents and wipe-on products for horses, or chemicals to treat all your cattle. Customers in regions with a long fly season might need to replace the sheets every year, whereas in other areas the sheets might last for three years. Bonacquista replaces his every two years.
The trap works best in an open area where flies can see it from a distance. When set up, it's about five feet tall and seven feet long. All you have to do is scoop out dead flies every other day or so with an aquarium net, add more water and soap if needed, and change the water about every two weeks. There's no messy bait to handle, and it doesn't matter what kind of dish soap you use. If the trap is in a pasture or barnyard, you can put an electric wire around it so animals won't rub or damage it. “We have ours set about 12 feet outside the pasture so the horses won't bother it,” he says.
Many people haven't heard about the trap even though it's been on the market since 1999. “Farnam never promoted it much. They probably preferred to sell sprays, wipes, etc. because there was more money in selling those continually rather than a fly trap once,” says Bonacquista.
For more information, check the website: www.horseline products.com or call 800-208-4846.