In the Pacific Northwest, our mild winter weather often cause a long and serious fly season often lasting from early April into late October. That means spring is the time to plan your attack on the coming season's flies. In this handout we will review some environmentally sensitive methods for reducing and managing the fly and insect population on your farm or horse place. This will in turn reduce your need for the amount of insecticides used around your farm and thus your impact on the environment. Plus it will make your place healthier for your horses and more enjoyable for you and your neighbors.
First off, no matter how much fly control you use there will still be a certain amount of flies, particularly on those hot sunny days. Filth flies carry diseases and can quickly cause problems such as conjunctivitis in your horse's eyes or infection in a wound. Biting flies, mosquitoes and insects such as Cullicoidies (No-See-Ums or Punkies) can cause your horse a lot of aggravation and complications due to itching. Regular applications of insecticides will still be necessary to control the insects in your area that bother your horses or animals. Consult your veterinarian for the type of fly spray they recommend and for the frequency of application. Be sure to read the directions on the bottle before handling and applying it. Also, a wonderfully safe method of fly management for horses is a physical barrier -- fly masks. Most horses learn to appreciate them enough that they come to you to have their fly nets put on. Remember to remove them each evening and before riding.
Good options for environmental control of insects include using beneficial insects and non-insecticidal traps, putting the local wildlife such as bats and birds to work, and reducing the insect habitat around your horse place. Use of these techniques will help reduce pesticide use and your impact on the environment.
Fly parasites are gnat-sized, nocturnal wasps which lay their eggs in the developing pupae of flies, thereby reducing or eliminating the fly population. They do not harm humans or animals in any way -- in fact, you won't even notice their presence. I've been using fly parasites at our place for about 5 years and we are very pleased with the results. We often don't even realize how effective our fly parasites are until we visit other stables and see the amount of flies around. There are many companies that sell fly parasites, even some local garden stores which sell beneficial insects and fly parasites. Two companies I've worked with are Kunafin, 1-800-832-1113, or Farnam Equipment Co., 1-800-234-0592. There are other sources listed in the backs of horse magazines, in gardening catalogues and through local businesses.
Pheromone traps are simple jars with one-way lids. The traps are placed in barn areas where flies hang out. A small amount of pheromone solution, a natural substance to which flies are attracted, is placed in the jar, The flies buzz into the jar, can't get out and die. Traps are sold by different companies under various names such as Trap-A-Fly, Venus Fly Trap and Fly Terminator. They can be ordered from most farm or vet supply catalogues such as Jeffers, 1-800-533-3377.
Bait jars are another effective way to trap flies. You can make your own fly bait jars very cheaply and easily. Take an old mayonnaise or similarly sized jar and punch several holes through the lid. Then put in a few pieces of raw hamburger or fish and about an inch or so of water in the bottom of the jar, Set the jar in a safe place where it won't be stepped on and very soon the flies, attracted by the smell of the meat, will make their way into the jar and eventually drown. The disadvantage to this method is that it can be smelly and particularly attractive to your household dogs. But it is a very useful method that your grandmothers probably used to use on their farm!
Another way to reduce the insect population (or at least keep them in check) is to encourage bats to take up residence near your horses. Bats play an important part in every healthy environment. Bats eat the nocturnal insects that plague us and our horses at night, such as mosquitoes. One bat can eat up to 600 mosquitoes an hour, more than 5,000 a night! They also eat other agricultural pests such as corn borers, cutworm moths, potato beetles and grasshoppers. In Europe, bats are highly valued for their insect control capabilities and have been protected for over 60 years. Europeans build and display "bat houses" much the way we build Purple Martin houses in the Midwest. In the United States, many old-time farmers still use insect control such as this.
Bat houses can be placed on a barn, pole, tree or the side of a house. The best habitat for bats is within a half mile of a stream, lake or wetland. Bat houses need to be placed by early April and it can take up to two years for a bat colony to find your house.
Bats are extremely particular about the houses that they will use. Be sure that any houses or plans for building them reflect up-to-date information on their needs.
A word of caution: because of the concern for rabies which can be carried by bats (or any wild, warm-blooded animal) consult your veterinarian for their recommendations on vaccinating your horses against rabies, even if you don't have bat houses in your yard. But remember, only of 1% of all bats actually have rabies, which is about similar for any other wild animal.
For the Birds
Encouraging insect-eating birds to move into your yard and barn area is another way to further reduce the amount of insects pestering you and your animals. Violet Green Swallows can be a tremendous asset to horse places -- one swallow consumes about 6,000 insects per day! That's better than any bug zapper and safer than insecticides! During the spring and summer in western Washington, the Violet Green Swallow can be seen diving and darting through most of our horse farms and neighborhoods. Nesting boxes specific to the Violet-Green Swallow can be built or purchased. Boxes should be placed out in April on the east or west side of a building about 8 to 20 feet off the ground. Locate them with an unobstructed approach and separate additional boxes.
You can purchase low cost nest boxes or receive plans to build the boxes yourself from the Rainier Audubon Society. Call or write them at 253-939-6411 or at P0. Box 778, Auburn, WA 98071.
Plans for building other bird houses and information on encouraging birds to your area are available through the WSU Snohomish County Cooperative Extension at 425-338-2400 or Rainier Audubon Society at 253-939-6411. For more information on creating habitat in your yard for birds, contact the WA Department of Wildlife in Mill Creek, WA at 206-775-1311 or this conservation district.
Of course, the very safest method of insect control for you, your horses and the environment includes reducing the breeding ground for flies and insects- mud and manure. A sound manure management program consists of picking up the manure in stalls and confinement areas on a daily basis and developing a composting or manure storage area. A simple cover or tarp helps prevent the nutrients from being washed off in the rain and contaminating the surface water and creating more mud. Gutters and downspouts on farm buildings help divert clean rainwater away from animal confinement areas thus reducing the amount of mud insects live in.
For More Information...
If you are interested in visiting some small farms that use these environmentally sensitive insect controls as well as mud and manure management techniques, contact the King Conservation District about the its education program and the King County Model Horse Farm Program. If you live in King County and would like a free manure and mud management system designed for your horse place, or if you would just like to have some questions answered, contact the King CD about a Farm Plan.
Permission to reprint this article is granted by the King Conservation District. Updated Spring 1996