Green Fly Control

Sharon Biggs

Flies and mosquitoes are not only irritating to animals and humans but they can carry deadly diseases too. Green stable managers can find respite for their horses with many natural measures.

More and more people are turning to biological control to help cut down the lifecycle of insects. One in particular is a beneficial insect called a fly parasite, which is used as a tool to work with nature. These are tiny parasitic wasps that are harmless to humans and animals, but not to flies. Released on manure piles and in barns, they will travel up to a two hundred foot radius to seek and destroy flies in their pupal stage. Available through mail order, fly parasites are inexpensive, safe and easy to use. Make sure to read the information on the proper way to release them, and get the right number or parasites for the amount of horses that you have.

For best results release the predators before fly season begins (Arbico Organics, which sells natural pest control, says this is usually when you have three consecutive days of 40 degree temperature), otherwise it will take up to 30 days for existing adults to die naturally. If you use fly parasites you're going to have to forgo any overhead sprays or direct spraying to your manure pile. Traps, zappers and horse sprays however, are fine. Parasites are usually shipped as fly pupae in sawdust. Spread small amounts every three to four weeks in or around problem areas, such as manure piles, under water troughs and in pens and paddocks.

Feed-through products also help disrupt the breeding cycle of flies. Feed-through fly control has an insect growth regulator as its active ingredient that travels within the intestinal tract and is passed in the manure without being absorbed in the horse. The active ingredient in the manure prevents house and stable fly larvae from developing an exoskeleton, so they can't become flying adults. Since the product kills the larvae and not the adults, feed-through products need to be fed for four to six weeks before the full benefit is seen.

According to the University of California at Davis, Division of Agriculture and Natural Resources, there is a bacterium that wreaks havoc with mosquito larvae. Bacillus thuringiensis var. israelensis, also known as Bti, turns toxic in the mosquito gut. It also affects blackflies and some midges. Bti comes in a noninfectious concentrate (spray-able liquid, granules and floating briquettes) that can be dunked or scattered in standing water such as water troughs, ponds, compost heaps, old tires, tree holes and bird baths. Bti can kill within 24 hours and up to three weeks, depending upon the product.

Mosquitoes are hard to kill without chemicals once they've developed into flying adults, but carbon dioxide mosquito and biting insect traps can help bring the population down. These traps work on the principle that mosquitoes located humans and animals by the C02 in the breath. The machine lures the bug with C02 created by a propane tank, trapping and killing them once inside.

Control pests' breeding environment by mowing grass low and remove all unnecessary standing water such as old buckets filled with rainwater and damp vegetation. Insectivorous birds and bats consume thousands of flying pests every day and night. Encourage them to stay by setting up bat houses and birdhouses near your barn.


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