Biting insects can turn ferocious this time of year, it's their last big hurrah. No matter how much fly control you use, there will still be a certain amount of flies, especially on those hot, sunny days. However, there are some ways you can keep your equine friends more comfortable.
Biting flies, mosquitoes, and insects, such as Cullicoidies, can cause your horse a lot of aggravation and complications due to itching (at the least), and by bringing disease (at the worst). Filth flies can quickly cause problems such as conjunctivitis in your horse's eyes, or infection in a wound. And of course mosquitoes can be carriers of West Nile and other viruses.
In years of summer drought, reduced water sources can trigger more birds and insects to carry the West Nile virus, creating the possibility of outbreaks in horses and people, particularly in areas where there have not been large outbreaks in the past, according to a study released by UC Santa Cruz.
Options for late season control of biting insects:
- Purchase fly parasites via mail order, from a reputable dealer, to stop the breeding cycles of flies if there are more than a few weeks of fly season left. It is best to start beneficial insects before fly season, when they can reduce flies populations by up to 70%, but in late season they can still help reduce fly populations.
- Use non-insecticidal (pheromone) traps for flies and yellow-jackets, and place them away from barns and on the fringes of paddocks, to lure the insects away from your horses and barn.
- Use non-toxic rolls, or sheets, of sticky fly paper—these can trap a large amount of flies as they become slower late in the season. Place these out of reach of horses, or where birds may become entangled in them.
- Attract and keep insect eating birds around by providing fresh water sources for them, and think about providing nesting boxes next spring.
- Reduce habitat for mosquitoes (diligently check for and empty all stagnant water sources).
- Use fly masks and fly sheets to give horses some relief.
- Get air movement into the barn with appropriately rated and wired fans—mosquitoes, gnats, midges, and some fly species are kept at bay and off of horses by a light breeze.
- Keep horses inside during dawn and dusk hours when the mosquitoes are most active.
- Keep odors down: pick up and compost manure, deodorize urine soaked areas, keep garbage cleaned up or sealed from releasing odors that will attract flies and yellow-jackets.
- Wash sweat off horses.
- Use either natural fly spray (made from essential oils), or commercial fly spray on horses during severe outbreaks.
- Don't indiscriminately spray broad spectrum insecticides—they can cause resistance in pest populations. The pests will bounce back, while the beneficial insects that are already helping you, by eating fly eggs, maggots, and mosquitoes—insects like Rove beetles, Assassin bugs, Dragonflies, centipedes, and others—will be killed. If you need to use pesticide, use selective sprays that target specific species, and spray so as not to irritate horse and human respiratory systems.
- Keep building healthy soils and plants to attract beneficial insects, they will come, and they will work hard for you!