Fight Nature with Nature: Natural Ways to Control Bugs, Part 2

by Alayne Blickle, Horses for Clean Water

In this series we help you plan your environmentally friendly attack on the season’s flies and insects. Last month we talked about several important points, including having a good manure and mud management program for your property -- which goes a long way in reducing the nuisance insect population on any horse property. This month we pick up with using beneficial insects as well as putting the birds and bats to work for you.

Good Bugs
Fly parasites are gnat-sized, nocturnal wasps that lay their eggs in the developing pupae of flies, thereby reducing or nearly 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 on our horse farm for many 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 number of flies around. There are many companies that sell fly parasites--check for ads in horse magazines, look in horse or farm supply catalogs, or do an Internet search for “fly parasites.” Local garden stores that sell beneficial insects such as ladybugs might carry fly parasites as well.

For the Birds
Encouraging insect-eating birds to move into your yard and barn area is an excellent means of reducing the flying insect population. Swallows can be a tremendous asset to horse places; one swallow consumes several thousand flying insects per day! That’s better than any bug zapper and safer than insecticides.

During the spring and summer in the Northwest, Violet-green Swallows can be seen diving and darting through most horse farms and neighborhoods. In early spring we collect horse and dog hair and set it out in tufts, then sit back and watch the antics as the swallows swoop and dart to snatch up bits as nesting material. Most years we have four or five nest boxes full of swallow families. Nesting boxes specific to the type of swallows in your area can be built or purchased. Check the March 2007 edition of The Green Horse for blueprints. You can also consult your local Audubon Society, birding organizations, cooperative extension service office, or the library.

That’s Batty
A great way to reduce the nocturnal insect population is to encourage bats to take up residence nearby. Bats play an important part in every healthy environment. They eat the nocturnal flying insects that plague our horses and us at night, such as mosquitoes; one bat is said to eat several hundred insects per hour, totaling more than 5,000 each 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. In the United States, many old-time farmers still use bat and bird houses specifically for insect control.

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.

Bat houses can be ordered through garden catalogues or purchased at stores. Be sure to check with experts in your area for the type of bat house necessary for the bats specific to your location. Find blueprints for bat houses on the Internet by searching for “bat house plans.” Also, check the library for books on how to build bat houses.

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 recommendations on vaccinating your horses against rabies, even if you don’t have bat houses in your yard. But remember, only 1/2 of 1% of all bats actually carry rabies, with similar numbers for most other wild animals.

Next month we conclude the series on green insect control by covering some simple, non-insecticidal traps for insects. We'll also cover some resources for more insect control help.

Until then, good horsekeeping to you!
~Alayne