Summer Fly Control

 

This time of year if you live on a farm, especially if you have animals, fly control is something that is likely at the top of your list of concerns.  Flies are not only an annoyance but can potentially spread disease, so keeping them to a minimum on your farm should be a priority.  

There are several species of flies found in NC; these are the most common fly pests found around the barn:

Stable fly: Bite by piercing horse's flesh to feed on his blood. These are the bugging bugs that gnaw on horses' legs, causing them to stomp, squirm, and flick their tails.

 

Housefly: With sponge-like mouths, houseflies feed on secretions, manure, and garbage; don't bite, but suck up secretions around wounds and horses' eyes, nostrils, and anus.
 

Face fly:  Females feed on secretions around eyes and nostrils, and on blood from biting flies and wounds. They have sandpaper-like tongues that abrade eye-area tissue to stimulate flow of tears (can cause infection, and even blindness).
 

Horn fly:  Half the size of housefly; pierce horse's skin to suck blood; prefer cattle, but attack nearby horses; can fly up to 10 miles, but then stay with same animals for the rest of their lives.
 

Bot fly:  Lay sticky eggs on horse's hair coat and on muzzle, jaw, lips, throat, and insides of legs. Larvae hatch in horse's mouth and later migrate to and live in his stomach and intestines; can cause poor condition, and even death.
 

Gnat:  Also known as "no-see-ums"; size of pepper grain; painful bites can cause sweet itch (persistent skin break-out that itches fiercely); itchy, crusty sores can cause horse to rub off patches of hair; most bothersome at dusk and dawn.

So we know who they are, now how to control them; it all starts with environmental management:

Scoop that poop:  Flies love poop.  Keeping your barn stalls, aisles, pens and any other area close to the barn cleaned up will help decrease the number of flies attracted to that area.  If you are composting your manure you will want to have your pile as far away from the barn as possible. 

Don’t feed the flies:  Keep your garbage in a container with a tightly closing lid.  Keep all grains and other feedstuffs in a container with a lid as well.  Pick up any animal food not eaten immediately.

Blow em away:  Flies have a harder time navigating a windy landscape so having fans in your barn will not only keep you and your equine friends cooler but will make your barn a less desirable place to be for winged pests.

If after employing your environmental management measures you are still battling flies, it’s time to try anti-fly weapons.  Here are the most commonly used and most effective:

Topicals
(sprays, roll-ons, gels, shampoos)

Method: Make your horse less attractive to flies.

How they work: Serve as a contact repellent/vapor barrier to fend off flies. Topicals with natural (pyrethrums) and synthetic insecticides work to "knock down" or deter flies; products without insecticides repel via citronella and other oils.

Pros: Easy to find and use; convenient for on-the-road use, such as when showing or trail riding, or when horse is away from barn for schooling or on pasture.

Cons: Relatively short-lived, depending on product; if you frequently bathe your horse, or he sweats significantly, you'll lose effectiveness.

Time factor: With lower-priced products, apply daily or directly before riding. For higher-end products, apply every five days to two weeks (see product labels for specifications).

Best when: Used in conjunction with feed-throughs or fly parasites, which kill flies at the larval stage.

Barriers
(sheets, masks, boots)

Method: Outer protection/barrier for flies and other biting insects.

How they work: Fly sheets: Lightweight mesh protects horse from withers to rump; many also offer neck, chest, and belly protection. Fly masks: Protect critical facial areas; styles vary: some cover eyes only, some extend over ears, some down over muzzle. Fly boots: Cover sensitive skin on lower legs.

Fly sheets and masks provide a barrier from flies and other biting insects.

Pros: Mesh material prevents horses from overheating; many barrier-type products offer sun protection (good for horses with exposed pink skin); masks help prevent conjunctivitis; sheets also protect coats from dirt and sun-bleaching.

Cons: Some sheets don't protect sensitive areas like the face and belly; applying and maintaining equipment requires some elbow grease; not practical if you're the sole caretaker of more than a few horses; can be dangerous if herd mates pull/bite sheet or masks, or if horses are pastured in brushy or timbered areas.

Time factor: Minimal to medium: applying/removing sheets, masks, boots when necessary. (For horse's comfort and visibility, it's recommended to remove masks at night.)

Best for: Horses living in close proximity with cattle or other livestock that attract horn and face flies; horses boarded at a facility without a broad fly-control program. Masks with ear covers are also helpful in areas plagued by gnats.

Traps
Method: Entrap (and kill) adult flies.

How they work: Many different types, but all use some variation of fly bait or attractant to lure flies onto sticky surface or into receptacle, where they die.

Pros: Can kill flies in specific areas without putting insecticides into the air; help manage adult flies missed by other fly-control methods.

Cons: Most traps only attract "filth" flies (house and blow flies), so you need to determine the types of flies you're targeting. Houseflies are usually the biggest problem for horse owners; if you have stable flies, you'll need a different type of trap.

Time factor: Depends on traps, but usually requires minimal set-up time. Some traps last for a season; others need to be replaced more frequently.
 
Best for: Almost all situations; useful regardless of other implemented methods, because traps control adult populations.

Barn Spray Systems
Method: Kills flies, mosquitoes, and other insects on insecticide contact.

How they work: Tubing system with attached misting nozzles runs throughout facility. Tubing dispenses fine droplets of fast-acting natural insecticide (pyrethrum) into air from an on-site reservoir. Insecticide is mixed with water and is sprayed for about 35 to 45 seconds. On average, a system sprays about six times a day.

Pros: Extremely efficient, effective. Minimal work, as dispensed automatically at regular intervals. Kills flies quickly, so they don't survive long enough to develop or pass on immunities to the insecticide. Short-lived pyrethrum is environment-friendly, as it biodegrades within 30 minutes of spraying.

Cons: High initial cost; some horses/people are sensitive/allergic to chemicals; kills beneficial insects such as spiders; manure close to barn still provides breeding grounds for flies (can also install nozzles along outside of barn).

Time factor: Refill tank a few times a year.

Best for: Medium- to large-sized enclosed facilities with multiple horses. (Can use in open barns, but not as effective, especially in areas with high winds.)

Biological Warfare: Fly Parasites
Method: Kills developing flies.

How they work: Release fly parasites (tiny, low-flying wasps) near manure piles and other fly-breeding sites. The parasites use the fly pupa (cocoon) as a host, killing developing flies so they never hatch. Prevents new generations from maturing.

Pros: Stops flies before they emerge and reproduce; no chemicals involved; doesn't kill beneficial insects; safe; low maintenance; parasites don't bite or sting people/horses/pets.

Cons: Doesn't affect water-breeding flies like horse and deer flies; if your neighbor doesn't have good fly control, his flies can migrate to your facility; must replenish monthly, as flies reproduce nine times faster than parasites.

Time factor: Five days after receiving them, parasites will emerge from pupa as active wasps. After releasing them, can take up to 30 days for noticeable results, because parasites don't affect flies that have already hatched. Best to release before flies become rampant. But, once in circulation, you'll only need to release new parasites every three to four weeks.

Best for: More condensed facilities, but effective in almost all set-ups.

Feed-Throughs
Methods: Prevents flies from hatching in manure.

How they work: Given with horse's grain ration; passes through his system, into manure to prevent larvae and pupa from developing there.

Pros: Safe; easy to use.

Cons: Don't kill adult flies; kills some beneficial microorganisms; ineffective if other horses in facility not on feedthroughs (horses also need to be fed separately to ensure all ingest complete dosage).

Time factor: Two to four weeks to see results; feed with horse's daily rations from early spring to late fall.

Best when: Used in conjunction with fly traps and topicals; works for facilities of any size.

This article was adapted from the article: Defeat the Enemy: Fly Control Options for Horse and Barn. https://www.equisearch.com/articles/horse-barn-fly-control