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Flies Outside

Black fly Deer fly Horse fly Mosquito stable fly
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What they look like
Big or small, all flies have two wings. Most are beneficial, helping you with garden pests and pollinating flowers.  The common pesky flies are: House Flies—The same ones you find inside. Don’t bite, but invite themselves to your picnic. Black flies or gnats—small, but big-time annoyances with painful bites. Stable flies—Same size as a house fly but bite with a lance-like mouthpart sticking out in front of their head. Usually bite your legs. Horse flies— Lots of kinds, but all are all big and all bite. Circle before landing. Deer flies— Dark blotches on clear wings. Attracted to a moving target—like you on your lawnmower. Mosquitoes—Hear a high-pitched wine? These dainty flies are known worldwide for the trouble they cause.

Where they live
Many biting flies spend their youth in water. If you live near a stream or swamp your yard will be prone to these pests. Horse, deer, and black flies hatch in flowing rivers or muddy shores, so getting at them isn’t easy. But dealing with mosquito, stable, and house fly breeding sides is doable. Old tires, unused plant pots, buckets, tarps … all collect pools of rainwater mosquitoes lay eggs in. House and stable flies lay eggs in rotting stuff: manure piles, grass clippings, uncovered garbage.

What they do

Besides those painful or itchy bites, flies spread diseases. Though mosquitoes in New York don’t pose a major health threat, planet-wide they’re the deadliest animal in the world.

How to deal with outdoor flies

Dump standing water: drill holes in old tires, clean your gutters, don’t pile grass clippings, keep the trash can covered, dump and replace water in birdbaths and wading pools weekly.

Consider insect repellants —but read the label first.

Putting up traps? , Site them away from your deck or garden—You don’t want to attract flies to your spot.

Don’t bother with bug zappers—flies ignore them. Besides, they often kill beneficial insects.

Learn more

What's All the Buzz about Mosquitoes?

¿Qué pasa con el mosquito?

NYS IPM Fact Sheets for Livestock

Contact your local Cornell Cooperative Extension office.

... and search our database of online publications.