Flying insects are bad news. At their worst, they transmit germs that cause Equine Infectious Anemia, West Nile Virus and other diseases. The challenge for horse owners and barn managers is how to diminish the populations of these undesirables without putting our horses and us at risk. The best advice is to go on the offensive. “Keep it clean,” says Olympic dressage veteran Michael Barisone, who keeps horses in New Jersey and Florida. “When it comes to controlling flies on our property, that is the single most important thing.” This includes sweeping up spilled grain, carrying off wet hay and keeping the manure pile tidy and away from the barn.
Trainer Gigi Nutter, who lives in Georgia, agrees that cleanliness is crucial. The manure buckets in her barn are scrubbed after stalls are cleaned, and manure is quickly removed from the barn. To the mantra “keep it clean” Nutter adds “keep ’em away.” While she finds fly sheets too hot for her climate, she always uses full fly masks with ears when horses are turned out. She keeps a fan mounted safely in the corner of each stall. The breeze also makes the environment less desirable for flying insects. Nutter has downsized from her 60-something horse barn in Pennsylvania. She may have fewer animals and milder winters but the addition of venomous spiders make the challenges just as intense. Cleanliness and physical barriers are just two prongs in her attack against insects, including an insecticide fogger. In summer, she fogs three times a week when the horses are outside. She closes the barn, covers all water buckets, hay and grain sources and whoever does the fogging is covered head-to-toe to avoid breathing in the chemicals. She keeps the barn closed for 45 minutes before opening it to air out. Two hours later she brings the horses back into the barn. She also mists the sawdust with a commercial fly spray and puts fly strips and traps around her property.
Oscar Merlotti has become the fly system installer to the equestrian stars, which includes Barisone in Florida. His Florida Bug Busters LLC has installed systems in 1,400 U.S. barns as well as in Argentina, Chile, Costa Rica and Columbia. A horseman himself who manages 300 horses at three Florida barns, Merlotti has a good feel for the negative impact of flies and mosquitoes. His system begins with a tank of water-based solution that includes natural pyrethrins—a natural compound derived from a particular Chrysanthemum flower. A pump delivers it to a series of perforated plastic tubing lines in the ceiling of the barn. It mists over each stall for 45 seconds every hour, thanks to a timer. “This solution requires no precautions like the oil-based solutions,” he says. “It goes into the stall, onto the horses and sometimes onto the people, too. In eight years I’ve never had anyone experience any kind of reaction.” He does avoid spraying stored hay as moisture damages hay over time. The effects of the solution do not last through work and sweat, though, and for that he recommends spraying the horse before work with a commercial fly spray.
To eliminate mosquitoes, which have a maximum range of about three miles and often stay within several hundred feet of where they were hatched, start with getting rid of all breeding sites, such as standing water in old tires, abandoned buckets, drains, flower pot saucers, gutters and abandoned pools. Nutter says she sometimes adds Mosquito Dunks® to standing water because it destroys mosquito larvae.
There is no single tactic for eradicating flying insects from your barn safely. Knowledge, however, is power. As insect types and behaviors vary greatly by geographic area, your local extension service can be a great resource. Know what these bugs like to eat, where they like to hang out, how they breed and you will have a leg up on making your property inhospitable for them and more comfortable for you and your horses.