General Sanitation

It sounds simple, but overall sanitation is still the most important and effective way to control flies. A little extra work “neating up” can yield a big fly reduction.

All outside trash and manure areas should be kept clean. Use garbage cans with tight fitting lids, lined inside with plastic bags. By placing garbage in secure plastic bags, odors will be reduced, therefore attracting fewer egg-laying flies. Locate the garbage cans as far away from the house or buildings as possible.

Dispose of garbage or manure weekly as House Flies take a minimum of 8 days to emerge. Sending your fly problem to the dump or back forty is much preferred to keeping it at your barn.

Eliminate other potential breeding materials. This includes rotting round bales, loose straw, mulch, leaves, manure, garbage, and moist soil with animal manure. Compost or manure piles that are not being added to frequently can be covered with black plastic which will increase the heat of the decomposing organic matter, destroying fly larvae. Avoid leaving moist pet foods outdoors for several days. Remove fallen, fermenting, or over-ripe fruits from the ground.

Any potential breeding material should be spread thinly in the field and allowed to dry to prevent fly development. The goal is to get the manure or other matter dry within five days as that is the minimum time for a House Fly to pupate. While forming their cocoon (pupate) if they are in a medium that is drier (or wetter) than 40-60% moisture by weight, the pupae does not form properly and that particular fly never completes its development.

Dispose of road kill animal carcasses quickly during the summer. Otherwise, they will quickly become “fly factories” within 24-48 hours. A small animal (i.e., dead cat, ground squirrel, tree squirrel, rabbit, etc) can easily produce more than a thousand Blow Flies if left by the side of the road. Dead deer, left to rot in a ditch, can yield tens of thousands of flies. You should report such problems to your county road department or other responsible authority and ensure that the carcass is promptly removed.

Manure Management

For most animal owners manure management is THE most important variable in any fly control program simply because this is the largest single source of (from a House Fly’s perspective) 'the good stuff.'

There are three typical programs that can be used to help control flies:

(1) Daily collection of fresh manure and spreading it thinly on crop and grassland areas. If spread properly and within a very few days over a wide area, fly attraction and control is seldom a problem in areas that receive little moisture during the summer.

(2) In areas that receive regular summer rains, more preferable is to collect the manure frequently and stockpile it in a compost pile. If properly constructed, there will be very little if any pest flies breeding in the compost pile. The decomposition of manure generates substantial heat and reduces the suitable fly breeding area to the outer 6” of the pile. If necessary, cover the pile with black plastic to increase decomposition. Periodically, composted manure can be applied to yards, gardens or pastures for disposal and to increase the soil condition and fertility.

(3) Perhaps the most common method, but least optimal, is pen and corral cleaning only after fly and odor problems have gotten out of control and your neighbors (or spouse) have been complaining for weeks. In this scenario, releasing extra Fly Predators can postpone, but not eliminate, the inevitable.

Clean stalls, corrals, paddocks, cattle pens, drainage areas, loafing sheds, feeding aprons, spilled feed, pet droppings and other decaying organic matter at no more than a 7 day interval to minimize fly breeding. This is because House Flies take a minimum of 8 days to emerge at optimum summer time temperatures. Daily pickup is preferred, but if you remove those pupae before the flies have emerged, the difference can be enormous.

In commercial facilities liquid wastes can be pumped from holding pits, in the spring or fall, to be spread over or injected into fields. Spread manure from a compost pile or pit in the spring, as soon as the fields are dry enough to travel on with spreading equipment. In the fall, after harvest is complete, is the second best time. Pick a time when weather conditions are cool to reduce both nutrient loss and odor problems, which is helped by immediately incorporating the manure into the soil.

More Rain = More Flies

If you have more rain than normal you will likely see more flies. Since pest fly eggs and larvae need to be in a moist medium, if it’s wetter than normal more breeding areas will stay 'just perfect' longer for producing lots of flies.

Flies have a staggering reproduction potential with each female fly laying up to 900 eggs. Thankfully due to natural predation (from beneficials like Fly Predators plus beetles, mites, ants, birds, etc.) plus the need for a moist environment for development, only 2-4% of fly eggs generally make it to adults. But a small favorable change to factors affecting their survival rate, like more rain (or decimating the beneficials with pesticides) can mean a huge increase in the numbers of flies. This is one of the reasons why there are “good” and “bad” fly years. Also, it only takes one burst of wet weather, in an otherwise dry year, to yield a larger than normal hatch of flies who then can hang around for nearly a month.

If you do have a rainy spell, by reacting quickly and stopping the extra reproduction before the fly population builds up, it will take less effort and cost than waiting until the flies are intolerable. Often quickly adding extra Fly Predators, plus more traps can bring the pest flies back under control within weeks.

Weed Control

Flies rest in weeds. Keeping it mowed “encourages” them to go elsewhere.

Surprising as it may seem, flies need a place to rest and get out of the heat or cool temperature. Weeds and tall grasses are perfect for this, so if you remove weeds from around buildings you can 'encourage' pest flies to hang out elsewhere.

Attractant Traps

There are innumerable different traps available on the market. The key point to understand is that there are different traps for different species of flies. There is no one trap that catches all species.

Most of the traps sold in feed, farm and hardware stores are for House Flies as they are the most common pest fly. Several popular types and brands are widely available and most use a non poisonous attractant in water (and the odor of the dead flies it catches) to draw in the flies. Many can have an effective attracting radius of about 100-150 feet.

The disposable traps are much easier to use as you simply discard them when full rather than having to clean out the jar. Your feed store is a good resource for the traps that work in your area.

Trap placement is important. If the farm has a small or moderate fly problem, traps placed close to the home or in the barn can attract flies from all over the area and make the problem worse. It is better to set the traps close to fly breeding sites with any prevailing breeze blowing from the trap toward the breeding area. Place traps well away from outdoor areas that are used for eating or recreation.

Traps should be placed near or on the ground and in sunny areas. If there is grass or weeds put the traps just above that. Don’t put traps in shady, dark or cool areas unless your temperatures are above 95-1000F. Attractant traps will not catch Fly Predators or other beneficials as they are not attracted by what is irresistible to a House Fly.

Sticky Fly Traps

Farnam EZ Trap™

Most Sticky Fly Traps, unlike Attractant Traps, can be hung in stables or barns as they do not draw House Flies from afar. Old fashioned fly paper or sticky coils are cheap but are not as effective as newer Sticky Traps such as the Farnam EZ Trap. Again if putting a Sticky Traps in a barn, then locate them down low in areas with sun light, not in dark areas.

Quick Tips House Flies

• Put Attractant Traps outside away from barn or home
• Put Sticky Traps/Tape in barn or stable
• Locate all Traps in sunny areas unless extremely hot, +950F
• Place Traps low, less than 4 feet

While not the favorite decor of most people inside the modern home or stable they are relatively cheap, safe and very effective fly catchers. They seem to be most effective against House Flies because these flies tend to rest on hanging vertical surfaces more than most other kinds of flies.

When choosing any trap consider the ease of disposal once covered or filled up (yuck) with the bounty of your local insect population.

From our position as “bug guys”, traps can be complimentary to get the remaining few adult flies that migrated in or were missed by Fly Predators. But if you’ve got flies galore and are depending on traps alone as your primary fly control you’ll need traps galore and that’s the hard way to fix the problem.

Horse and Deer Fly Traps

Horse Pal Horse Fly Trap™

The “HorsePal” Horse Fly trap has been reported to be effective for Horse Flies, Deer Flies, as well as Greenheads and Yellow Flies. These large biting flies are attracted visually to the black ball and when they discover the ball is not a source of food, they fly upward to leave. They are then caught within the tent and continue upwards into jar that captures them where they die from dehydration. Cost is $275 including shipping. Not inexpensive, but will last for years and can save you and your animals from very painful bites. More at www.horsepal.info

Stable Fly Traps

Farnam Bite-Free Stable Trap™

Horse owners mostly have House Flies, but some may have Stable Flies. However, most traps sold in feed stores will not catch Stable Flies.

So if you have flies that look like House Flies but bite like the dickens you have Stable Flies. If you want to catch these you need Stable Fly traps. Fly Predators will control Stable Flies, but you need to put them where Stable Flies reproduce.

Farnam offers the Bite Free Stable Fly Trap™ which is available in feed stores. Unlike House Fly traps which use smell to attract the flies, Stable Fly traps attract their target by visual means. So place these traps at least 10ft. outside of your barn, in sunny areas, where they can be seen by the flies. Stable Flies stay near the ground so put traps low, not more than 4ft. high. If you need to put them in pastures set them every 50–100ft. in places where your animals can’t mess with them. They’re not poisonous, just very sticky.

Reduce Inward Migration

A House Fly can easily travel 1/4 mile, so if you have neighbors with animals within that range some of the flies you’re seeing are likely from there.

The closer they are and the more animals they have the bigger the problem. Two horses 1/4 mile away are not a big issue, a feedlot across the street is. The biting flies can travel much further, in some cases many miles from their breeding areas, particularly if there is a strong prevailing breeze.

The best solution is to get your neighbors to control their flies, which means there will be fewer visiting you. If it’s only a few animals, purchasing some extra Fly Predators for their animals may be the most pragmatic solution.

If you can’t get your neighbors to control their flies (usually House Flies), or if the likely source of your Deer and Horse Flies is a boggy area, then put multiple traps, of the correct type, between you and the source of those unwanted “tourists”.

Poison Fly Baits

If you are not adverse to using poison fly baits, they can be effective and are a far preferred alternative to areaerosol pesticide spraying when using Fly Predators.

This is because the attractants in fly bait do not interest either Fly Predators or any of the other beneficials whereas most sprays are indiscriminate and kill all the good beneficials more effectively than the pest flies. This will make your fly problem worse in a few weeks. Normally baits will only be needed to quickly reduce an existing House Fly population if starting a beneficial program late, or if extra control is needed for an outbreak of adult flies due to weather or other temporary factors.

Your vet, local feed store or county ag advisor is the best source of information for what baits are effective now in your area. Understand that flies quickly develop pesticide resistance so 'old favorites' may not be as effective as newer products. ALWAYS read and carefully follow the instructions.

Other Beneficials You Want to Encourage

Dung Beetles

‘Dung Beetle’ is the common name for beetles that are members of the Scarabaeidae family. These beetles breed, feed and tunnel in dung deposited on pastures. Through their activities, these beetles break up and bury the dung pat. This dries up the pat and removes it as a breeding site for pest flies. Hence, Dung Beetles are most efficient in reducing numbers of flies if the beetles disperse and bury the dung within a few days of its deposition before the flies can finish their development. Dung Beetle populations can be decimated by the toxicity of manure from the use of de-wormers. So if you have Dung Beetles select a de-wormer that offers lower toxicity to beetles and other beneficials such as Fort Dodge’s Quest®, Quest Plus or Cydectin® for cattle.

Mites

Tiny Mites (1/32' or less in length) are found practically everywhere, including the breeding sites of the Stable Fly and House Fly. Predaceous mites, such as those in the family Macrochelidae can be important natural enemies of these pest species. By feeding on eggs and young maggots, one mite can kill up to 36 House Flies per day. In field studies, calf pen manure and outdoor piles of dairy cattle manure produced up to 67% and up to 45% fewer House Flies, respectively, when mites were present than did adjacent areas where mites were killed with the application of pesticides.

Tiny Mites (1/32” or less in length) are found practically everywhere, including the breeding sites of the Stable Fly and House Fly. Predaceous mites, such as those in the family Macrochelidae can be important natural enemies of these pest species. By feeding on eggs and young maggots, one mite can kill up to 36 House Flies per day. In field studies, calf pen manure and outdoor piles of dairy cattle manure produced up to 67% and up to 45% fewer House Flies, respectively, when mites were present than did adjacent areas where mites were killed with the application of pesticides.

Mites are among the first predators to colonize manure because they disperse by phoresy; i.e., they 'hitch-hike' on other insects. Hence, flies arriving to lay eggs in new breeding sites also may be carrying predacious mites that will feed on these eggs.

Mites can be best used by conserving their natural populations with the following practices: keep manure dry with good ventilation and good drainage, this will promote the growth of mite populations. Avoid the use of larvicides unless their effects are known to be limited to just the pest flies.