Know your enemy, the first rule of tactical warfare, also applies to the battle against the buzzing infiltrators in your barn. Whether talking to the Tufts School of Veterinary Medicine or a Texas ranch, horse owners agree that fly control involves a combination of assaults, and the more we learn about our resilient little foes, the better armed we are to win the war.
Fly Facts Of Life
Diptera, or true flies, are the insect world's success story. They're the only flying insects to have two, not four, wings. They come in more than 120,000 species in assorted shapes and sizes. Their diets vary. Some fly larvae will even eat other flies while others don't eat at all. And they can live just about anywhere -- in soil, fresh water, sea plants and, yes, our horses.
We're not just looking at an army of insects. Flies are the Special Forces Unit.
There's no avoiding them. Since humans started living in houses and keeping animals in barns, the common house fly, Musca Domestica, has been a constant companion.
So despite your neighbor's arguments to the contrary, horses don't attract flies. Flies already abound in rural and suburban areas, and while you may wish that you could annihilate them entirely, it's not a good idea.
"Flies have to exist," says Koyla Renaas, lecturer in Equine Management at the University of Massachusetts in Amherst. "They contribute to our food chain. But you can control them."
And you should. Flies have wreaked historic levels of havoc on horses and livestock. The Simulium species (black flies) spreads "sweet itch," and in 1923, the Golubatz fly killed 20,000 domestic livestock (including horses) in Romania, Bulgaria and Yugoslavia through bites and disease.
They can also carry some nasty human diseases -- typhoid, dysentery, tuberculosis, conjunctivitis, even plague. Two flies can produce 1.8 million breeding pairs within just 12 weeks.
Stop Them Before They Start
While flies live just about anywhere, you can make your farm a less-then-ideal environment. Here's how to keep the numbers down:
Keep it clean. "Cleanliness is your number one ally," says Renaas. Remove manure daily. Keep it dry by spreading. Rake up grass clippings and leaves for compost.
Cover it up. Cover manure piles or compost with plastic to prevent flies from laying eggs. Clean up spilled hay and grain, and either compost or store in closed trash containers.
Use an additive. Pelleted and mineral block feed additives safely pass through equine digestive systems and kill larvae in fresh manure. Rabon, fed at Tufts University, "poisons manure and becomes toxic to larvae, while remaining safe to horses," says Dr. Laura Armel of the Ambulatory division of the Large Animal Hospital.
Win with wasps. Turn your flies into another critter's dinner. Wasp eggs can be shipped to your barn each month, where they are spread in your manure pile. When they hatch, the wasps eat the fly larvae they find there. What happens to the wasps? "They go on to reproduce," says Renaas, who assures "they're smaller than stinging wasps and don't bother people."
Go bats. A fly's natural enemies are birds and bats. Barns naturally attract birds, but bats may need encouragement to take up residence near your barn. These nocturnal predators eat flies in the fields while your horses are bedded down for the night. To attract them, build a bat house ten feet off the ground on the warmest (southern) side of your barn and painted a dark color. Make sure dropping don't fall on feed or animals and be patient. It can take some time before bats answer your "For Rent" sign. If you invite birds near your barn clean up after them -- their leavings can be food for flies.
Drain water. Eliminate stagnant pools via good drainage, dumping and scrubbing buckets, and installing dry wells under outside faucets.
Scrub buckets. Scrub out feed residue to deter flies from eating there.
Put a lid on it. Cover feed bins to thwart flies from feasting. Don't leave bags open, both to eliminate spills and keep flies from feeding inside.
Take out the trash. Garbage is the equivalent of a fly's romantic boudoir. Keep it far from your barn.
Site it right. Build barns away from wet, low-lying areas, suggests USET eventer Bruce Davidson.
Play Keep Away
Try these measures to monitor fly populations:
Use screens. Arabian breeder Rebecca Bowland in Michigan swears by the 12" x 10" screens on her barn doors. At Tufts, says Dr. Carmel, they're adamant about keeping doors screened and closed.
Put out tapes. Cheryl Lekstrom, at Windcrest Acres in Massachusetts, lines windows and doors with fly tape to catch intruders. "I change it every few days. Unrolling the sticky tape is slow, and it does dry out, but it works."
Paint it on. Use a paint that repels flies. Products like Bug Ban can be painted on building exteriors.
Braid it in. Braid chemically-treated fly strips into manes or tails, or attach to the browband. Bay State Trail Riders Association member Pat Gillespie weaves pine branches through the bridle crown when she rides in deep woods. "The flopping of the giant forelock and the strong pine scent keeps flies away."
Let your horse do the work. When your horse is on R&R, let them roll in the mud to make their own natural fly repellent. Long tails, manes and unclipped ears also offer protection.
Give 'em a jolt. Electric zappers end fly problems as quick as "Zap!"
Try traps. Dr. Carmel makes traps from a plastic jar, filled with chicken fat or other rotting meat. "Flies go in, get stuck and can't get out."
Good Management Wins. The bottom line in winning the war on flies goes back to basic maintenance of your barn and the areas around it. Not only will it help end your fly problem, but it will also help protect your barn by providing a pleasant, clean and safe working environment.