Make Your Barn The Last Stop For Flies

When it comes to flies, there are two basic facts of life: First, you can’t eliminate them. Second, controlling them inevitably costs time and money, and anything that can reduce those costs is worth investigating.

There’s no arguing that applying insecticides to your horse and systems that mist the barn — including the stalls and horses — at regular intervals do control flies inside. However, since topical repellents are usually needed outside in pastures and the arena, we wanted ways to slash the fly populations inside the barn without directly subjecting the horse to more pesticide.

Use A Comprehensive Fly Program
No matter how effective your fly trapper, it won’t be enough on its own. Control is a multi-step process:

• Sanitation. You need to do more than just clean up manure several times a day, although that’s one of the best ways to keep the flies away from the horses. Fly-egg hatching depends on both a supply of organic material for the larvae — about one pound to produce 1,000 flies — and a fairly high moisture level. If you spread your manure rather than pile it, the rapid drying makes it unsuitable for fly larvae.

Larvae can also thrive in dead leaves collected inside drainpipes, even in piles of grass clippings. If you must keep organic materials, use covered pits or keep the mounds covered with heavy dark plastic. The plastic is a physical barrier, plus it increases the heat inside the pile to the point fly larvae are killed. In general, many of the same measures recommended for reducing potential mosquito-breeding sites apply equally to flies.

• Exclusion. A key component in successful fly control, but one that’s easier said than done in a barn, is keeping the flies out. Screening windows and doors is costly, but may be worthwhile in severe problem areas. Flies tend to collect along windowsills and doorways. Overhangs or awnings create a “buffer zone” of sorts and an area where you can install flycatchers to reduce populations before they even venture inside.

• Repellents. Coating the outside of buildings with insecticides specially formulated for this process is preferable to using heavy amounts of insecticides inside the barn, in the stalls and on the horses. However, this is a job best left to professionals, and care should be taken to not apply to walls within reach of a horse’s mouth.

• Know Your Flies. It pays to identify the types of flies you have problems with, as no one attractant will attract all types. Environmental control measures may vary, too. If you’re not sure what’s buzzing around, your local Cooperative Extension can probably tell you what flies are native to the area or help you identify them.

Flies vastly prefer calm-air areas to those with a breeze. They usually avoid the “work” of flying near fans, so fans placed in aisles, above the solid level of the stall walls, will help divert flies from entering stalls from the barn aisles. Place your traps and tapes above the level of the fans for peak effectiveness.

Fly Attractants
The deadliest trap in the world is useless if the flies won’t go in it. Manufacturers use a variety of lures to entice the insects, not all equally effective. When you consider a product, look at the variety of pests it’s said to attract. If your main fly concern isn’t listed, you need a different trap.


Biting flies, like mosquitoes, are the most difficult to attract, especially with live “food” in the vicinity. Heat, sweat and visual cues are the major attractants for these flies. Pregnant female stable flies, ready to lay their eggs, may be attracted to the foul-smelling liquid/drowning traps but won’t be in their biting/feeding stages.

Houseflies were strongly attracted to traps containing pheromones regardless of where they were placed. They also liked the foul-smelling liquid traps, especially if these were placed in the sun, which made them especially, well, fragrant.

With trapping systems claiming to use more pleasant, food-like scents, we either noticed no difference compared to plain sticky tapes or couldn’t tell because pheromones were also used, such as in the Paraclipse Terminator.

The UV light was a big hit with moths and fruit flies/gnats, but nuisance-fly kills seemed to be more hit or miss. Since the house and biting flies are most active in the daytime, the UV light is far less noticeable. It may have some effect when the flies come within a few feet of the unit. However, even at dusk with greatly decreased background light levels, and at night when only the UV traps were burning, we often observed flies resting peacefully in close proximity.

The chartreuse/yellow-green color of many sticky fly tapes is supposed to attract flies, but someone may want to check that out with the flies. We found flies sitting on walls or stall bars right next to yellow tape. White tapes, on the other hand, caught an average of 10% more flies. A few tapes also grabbed bird feathers.

Sticky traps with patterns on them, such as flies, spider webs or other drawings, were no more attractive to flies than those without — not that we’re sure they’re supposed to be. We didn’t observe any attractant effect when tapes had flies attached compared to fresh tapes, although an occasional loudly protesting fly did seem to warn off others to an extent.

Field Trials
The products were used under average barn conditions last summer. The severity of the fly problem in 2001 was rated as average to slightly above average. In our chart, we rated products from 1 to 5, with 1 as minimal catch/kill and 5 excellent catch/kill, with an emphasis on nuisance pests.

Bottom Line
If you’re looking for a product that irresistibly draws flies in your barn to their certain death, forget it. No product we tested matched the allure of a horse’s body or manure.

We found light and the color yellow basically overrated as attractants, especially in the daytime. White tapes faired better.


“Scented” traps (actually stinky was more like it with the drowning traps) and glue surfaces were more appealing than plain, with sex pheromones being most effective.

Electrocuting zappers are fun for the sadistic, but their kill is random and they produce a spray of bug parts and bacteria. We found the lights are more effective in drawing in moths, gnats and fruit flies than the major nuisance and biting flies.

Our best performer overall was the Paraclipse Terminator, which combines UV light enhanced by reflectors with the draw of pheromones and scents, trapping the flies on its sticky, self-advancing tape. The price is reasonable compared to the other electrocuting units. The Terminator was also highly effective, and use and maintenance were sanitary.

If you need a clock and night light in your tack room, consider the CB Aurora 360 from Country Vet. The glue disc with pheromone attractant gives the Aurora 360 trap a so rt of double whammy effect.

For maximum effectiveness at minimum price you can’t beat papering your ceilings with Catchmaster’s huge Spider Web glue traps. Mounting and maintaining ceiling coverage is a bit of a chore, but the traps do effectively reduce fly populations.

For less conspicuous daytime trapping, we liked the Coburn Mr. Sticky Roll glue ribbons for doorways. If you want to mount a tape near the ceiling and have barn birds, we prefer the Mr. Sticky narrow tape to avoid the birds getting trapped on the wider tape. Try the Eaton Stick-A-Fly Glue covered tubes for small areas, like feed rooms.

For diverting flies before they enter, try the Victor Fly Magnet. It attracted more flies, was aesthetic (until full) and is reusable.

Also With This Article
Click here to view ”Fly Smarts.”
Click here to view ”Horse Pal Reduces Pesky Horse And Deer Fly Pasture Populations.”
Click here to view ”Glue And Liquid Fly Traps.”
Click here to view ”Electronic And Light Traps.”

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