It is important to keep control over fly population which may irritate the farm animals and affect their performances. So here are few enlisted techniques which can be utilized to control or prevent flies on poultry farms
Accumulated poultry manure can be highly suitable for fly breeding, especially where general sanitation is poor and when there is excessive moisture. Suitable fly-breeding conditions can be present the year round in enclosed high-rise egg layer houses with long-term manure accumulation and in shallow pit houses in which manure is held for several months. In other types of poultry operations (e.g. breeder flocks, broiler/turkey grow-out houses) flies may also be of concern. In breeder houses with slatted floors flies can find breeding spots, especially under feeders and waterers, and wherever manure accumulations under the slats have high enough moisture content. In broiler and grow-out houses for chickens and turkeys, little or no fly breeding usually occurs because the entire floor is covered with relatively dry litter. Some fly breeding may occur in wet litter around the waterers, but this is usually a minor problem.
The house fly is considered the major pest fly species associated with poultry manure, especially in caged-layer operations. House flies are the primary cause of public health nuisance complaints in surrounding communities resulting in poor community relations and threats of litigation. The effective house fly dispersal range from their preferred breeding sources is from ½ to 2 miles with nuisance populations highest closest to their breeding source. Of public health concern, house flies are capable of harboring more than 100 human and animal disease-causing organisms.
When little house flies (Fannia sp.) are present, high populations can develop on poultry farms. Little house flies are less tolerant of hot, midsummer temperatures than house flies, and often emerge in large numbers in early spring, declining in midsummer, and peaking again in late fall. Although these flies may invade nearby residential areas, they tend to be less annoying in that they do not readily settle on food or people. Adult males show a distinctive aimless hovering or circling flight behavior of long duration within the poultry house or at outside shaded areas. Females are less active and more often found near breeding sites.
Several species of blow flies may occur in poultry facilities. They breed in decaying animal carcasses, dead birds, broken eggs, and wet garbage. Large numbers can be produced in a poultry operation if there are larger accumulations of broken eggs and if dead birds are not properly and frequently removed. Prompt removal of dead birds and rodents, preventing accumulation of broken eggs, and daily cleanup of processing areas is usually sufficient to prevent the build-up of these flies.
Small dung flies, along with several other small gnats, readily breed in poultry manure and other decaying materials. They can occur in large numbers in poultry operations but generally are not a nuisance on the farm or in nearby communities. Population levels are often higher in spring and late summer and fall.
Surveillance: A standardized, quantitative method for monitoring fly populations should be a part of a poultry fly pest management program for use in making control decisions and to monitor control effectiveness. Visual observations of fly populations alone are subjective. Of sampling methods available, the use of spot/speck cards and/or sticky fly ribbons are the most widely accepted.
Fly spot or speck cards consist of 3 inch x 5 inch white file cards placed in a poultry house upstairs in high-rise or shallow pit caged layer operations and/or in the manure pit. They can be suspended from strings or fastened to support posts, ceilings, or other areas where flies tend to settle (where there are larger numbers of fly fecal and regurgitation spots). Placement is also best where there is little air movement and where workers or equipment will not disturb the cards. Several cards can be placed in a facility, with date of placement and location noted on the card. Once placed, cards should be left for a period of 7 days and replaced with new cards at the same place each week. The number of “fly specks” on the exposed side (one side) of each card should be counted and recorded in a record keeping notebook or spreadsheet. Generally, 100 or more fly specks per card indicates the need for fly control measures. The use of spot cards is a simple, cost-effective, and widely adapted method for assessing fly populations week after week. It also provides documentation of fly activity over the course of time and the effectiveness of control efforts that can be helpful in resolving conflicts with neighbors over claims of increased fly activity.
Sticky fly ribbons/tapes are another means of monitoring fly activity in a facility. One method to use them is to select locations to hang them up for weekly intervals. However, used this way, they often tend to dry and get dirty over time and become less effective in capturing flies. A more suitable way to use them is to take a fresh tape, hold it out in front at waist level, and walk at a steady pace the length of house down one walkway between cages and back another walkway. Flies caught on the tape can then be counted and recorded. One to two fly tapes should be used per house at least once a week. Generally, 100 or more flies caught per tape indicates the need for fly control measures.
Fly Control: Four basic management strategies make up a successful integrated fly control program: cultural/physical, biological, mechanical, and chemical control.
Cultural/Physical Control: Management of poultry manure so that it is not conducive to fly breeding is the most effective means of control. Fresh poultry manure generally contains 60 to 80 percent moisture. Flies can readily breed in manure with a moisture content of 50 to 85 percent. Manure moisture below 50 percent is less suitable for fly breeding, and fly breeding usually does not occur at 30 percent moisture or less.
Dry manure management is practiced under two types of systems: 1) frequent manure removal (at least weekly), and 2) long-term, in-house storage of manure. Frequent manure removal systems to prevent fly breeding are based upon weekly (or more frequent) removal and field spreading it or transporting it to a holding area/composting site for drying/composting. This can be effective if done regularly and thoroughly, but it does require adequate and available agricultural land where manure can be spread or suitable facilities for holding manure or for composting. With belt manure removal systems belts need to remove manure two to three times per week. Fresh manure on belts is attractive for fly egg laying activity and fly maggots can develop if manure is not removed quick enough. These developing flies may then continue developing in manure storage sites once the belt removes the manure. With in-house storage of manure, efforts should be made to reduce manure moisture below 50 percent (preferably to about 30 percent or less) and to maintain this level.
In either system, any practice that limits moisture in the droppings or aids rapid drying is helpful. A few practices to follow include:
- Prevent leaks in waterers. Inspect the pit daily to check for leaks, and repair them when found.
- When the water table is high or there is a danger of water running in from the outside, adjust the floor/grade relationship so that the floor of the house is higher than the surrounding ground and water runs away from the building.
- Provide abundant ventilation both in the manure pit for effective drying and in the house for bird comfort.
- Avoid rations that are laxative.
- Use absorbent litter where practical.
- Maintain proper insulation on water lines to prevent condensation.
Adequate ventilation reduces manure moisture and maintains desirable air temperatures, removes gases such as ammonia, and provides fresh air. Exhaust fans located in the manure pit walls provide ventilation for environmentally controlled high-rise houses. Also, supplemental drying fans (three-blade, 36-inch, direct-drive fans) installed between manure piles in the pits will greatly increase manure drying, especially that of the fresh dropped manure on the top of coned manure. These supplemental fans should be installed about every 50 feet, positioned in the same direction in each row and reversed in position every other row to get maximum efficiency of air movement through the pit and manure surface. These fans should be kept free of obstructions and run during daylight hours when birds are most actively producing droppings.
In facilities designed for in-house storage of manure, accumulated droppings, if left undisturbed with adequate ventilation and free of additional moisture, will form a cone-shaped mound under the cages and allow for natural composting.
Undisturbed manure accumulations normally support large populations of beneficial parasites and predators of breeding flies. These parasite/predator populations primarily consist of predaceous beetles, mites, and parasitic wasps. The buildup of these natural fly enemies is usually slower than that of flies. Populations high enough to substantially benefit fly control can develop only if the manure is not disturbed for relatively long periods of time. To encourage parasites and predators:
- Maintain dry manure
- Remove manure in cooler months when flies are less active.
- Stagger manure removal over a few weeks to preserve beneficial parasite/predator populations.
- Minimize the use of insecticides in the manure pit/storage area.
In-house composting of accumulating manure is a practice that can be established to process manure and manage insect populations in high-rise layer houses. This process involves agitating the manure to incorporate oxygen and possibly a carbon source to aid in the composting process. This agitation results in increased temperature, an increased ammonia level, and decreased moisture content, all of which help reduce insect populations and makes the manure more valuable as a fertilizer source that is easier to handle when removed. The agitation can be accomplished either by installing in-house chain- or tract-driven turning machines or by hydraulic-powered portable manure turners that can be used in multiple houses. Turning the manure pile twice a week is usually adequate, but the best way to determine need is to take the manure pile temperature with a compost thermometer. The temperature should be at least 120°F before turning is implemented. Because this composting activity produces ammonia that is released in higher concentrations during the turning process, protective respiratory devices should be used by workers. Also, composting eliminates beneficial parasite/predator populations, so ceasing to compost after being initiated can cause large house fly outbreaks. Also, because most available composting equipment cannot continually turn high manure piles, the pit needs to be cleaned out when composted manure piles approaches 2 feet in height for most available equipment.
When manure needs to be removed from a facility, it is best to do so in cooler months when flies are less active and when cooler outside condition would minimize insect migration from field applied manure. Also, fresh manure that accumulates within just 2 days after house cleanout is ideal for fly breeding, often resulting in a severe fly outbreak to occur 2 to 3 weeks after a cleanout. When fly populations are low and less active during cooler weather this fresh manure will be less prone to a quick establishment of fly breeding activity.
During spring and summer, when fly and beetle dispersal is a major concern, manure that must be removed can be treated with an insecticide approved for such use to kill insects in the manure at the time of removal. Manure can also be piled in a field before spreading and either treated again and/or tarped to kill developing insects. Heat that develops in the manure pile under secure tarps will kill insects that are present. After about 2 weeks under the tarp, the manure can be spread on fields without concern for pest dispersal.
Additional sanitation practices are also important in fly control. Remove dead birds daily and dispose of them properly. Minimize accumulation of spilled feed and broken eggs that attract flies and pest beetles. On the outside, keep grass and weeds adjacent to poultry houses mowed to eliminate resting areas for adult flies and to allow for adequate air movement around the buildings.
Biological Control: As indicated above, cultural/manure management practices encourage the survival and buildup of beneficial predators and parasites that can suppress house fly populations. Keeping manure dry also encourages the increase in other insects that compete for nutrients in the manure habitat.
Such beneficial organisms as predacious mite (e.g. Macroceles sp.) and small black hister beetles (Carcinops pumilo) will readily feed on house fly eggs and first-instar house fly larvae. Another group of beneficial insects are tiny parasitic wasps (primarily in the family Pteromalidae). Female wasps oviposit their eggs in fly pupae. Inside the fly pupa, the developing larval wasp kills and consumes the fly before it emerges.
With proper dry manure management predaceous mite and hister beetle populations often build up in higher numbers. Parasitic wasps (often called “parasitoids”) usually occur naturally in lower numbers. Control using these parasitoids is sometimes based on mass releases of commercially reared parasitoids. Parasitoids are currently available from several commercial insectaries. For a release program to be successful, the producer needs to consider which parasitoid species are best suited for their particular operations and in what numbers to release them and when. Check with the suppliers of these parasitoids for recommendations.
Other insects, such as the darkling beetle (lesser mealworm, Alphitobius diaperinus) and dermestid beetles, often build up in high numbers under dry manure management. They can be beneficial in competing for the nutrients in the manure and prevent house fly buildup. However, they are responsible for damaging poultry structures (wood and insulation), harboring poultry disease organisms, and often being the cause of nuisance complaints when manure is transported and field applied when higher beetle populations are present in the manure.
A newer biological control agent has been developed commercially for fly control in poultry houses. A natural pathogenic fungus Beauveria bassiana has been formulated into a spray product (balEnce). This product is sprayed directly over accumulated manure. Adult house flies, as they emerge from their pupal cases, come in contact with spores of Beauveria. Spores released from the conidia develop hyphae which penetrate into the body cavity of the flies resulting in death. Beauveria fungus has no detrimental effect on beneficial insects including histerid beetles and pteromalid parasitoid wasps.
Mechanical Control: Screens and fly traps are two methods of mechanical fly control, if used properly. Where possible, doors and windows should be screened to prevent entry of flies, especially in processing areas. Several kinds of fly traps are available. Some traps consist of a fly attractant in a liquid to attract flies, while others are electrical, employing a black light with either an electrically charged grid to kill the insects or are equipped with sticky sheets to get attracted flies stuck. Traps do appear to be helpful in tight, enclosed areas where good sanitation practices are followed. However, in areas of heavy fly populations, traps are not effective in reducing fly numbers to satisfactory levels. They are best used as a supplement to other fly control procedures. Jug fly traps containing a liquid attractant can be strategically located around the outside perimeter of poultry buildings to help reduce adult flies near buildings. All fly traps need to be properly serviced and maintained to assure their optimal performance.
Chemical Control: Insecticides should be considered as supplementary to sanitation and management measures aimed at preventing fly breeding. Producers should monitor fly populations on a regular basis to evaluate their fly management program and to decide when insecticide applications are needed. Chemical insecticides can play an important role in an integrated fly control program. However, improper timing and indiscriminate insecticide use can lead to increased fly populations. Also, selective application of insecticides can avoid killing beneficial fly predators and parasites. Insecticide applications may be directed to adult flies (adulticides) or fly larvae (larvicides). Methods of application include sprays (knockdown, residual), baits, and feed additives.
Knockdown, non-residual space sprays, mists and fogs are designed for quick knockdown and kill of flies with no residual action. They are usually the most effective and economical method to control potentially heavy populations of adult flies. Because they do have very little residual activity, resistance to the insecticides recommended as space sprays is low, especially when using products containing synergized natural pyrethrins. Several pyrethroids are also available for use as quick knockdown sprays. There are many machines on the market designed to produce the small particle spray size desired for this type of application (e.g. backpack sprayers, cart mounted sprayers).
Space spray application should be made to the point of “filling” a room or area with the spray mist. Treatments should be made as frequently as needed to keep fly numbers down below identified nuisance levels. This method of fly control is best used in the cooler, early morning hours when flies are resting higher up in the house and ventilation fans can be safely turned off during the time of spraying without causing increased house temperatures. These insecticides should not be routinely applied in the pits of high-rise egglayer houses since they will kill beneficial insect populations present.
Treating building surfaces with residual sprays has been a common practice over the years. Dependence on this method has led to high levels of fly resistance to the available insecticides used as residual sprays (e.g. pyrethroids, organophosphates). Also, treated surface tend to quickly get covered over with dust, and this could reduce fly exposure on the treated surface. Residual sprays should be used sparingly and only as a last resort to control fly outbreaks that cannot be managed with other techniques.
Fly baits are a viable part of an integrated fly control program to maintain low fly populations. They are a very effective supplement to sprays. Commercial dry baits in granular and extruded form are readily available. They contain such active ingredients as methomyl Golden Malrin), imidicloprid (QuickBayt), and spinosad (Elector). Bait placement should be on walkways/aisles and other areas where flies congregate. Avoid application in the manure pit, since the available baits will kill beneficial parasite and predator populations. Baits must also be placed out of reach of birds and placed so they don’t contaminate food and water sources. Some bait/insecticide products are also available on hanging strips. One such product, containing nithiazine (QuikStrike), has shown to be very effective and fast acting when properly placed in active fly areas. Also, some bait products are available as brush on formulations or can be mixed with water to make a brushable slurry. Apply these treatments on surfaces where flies tend to congregate. Rotating the use of different bait products and active ingredients once or twice during a fly season will minimize the onset of fly resistance to any one active ingredient.
Direct application of chemical larvicides to the manure surface to kill fly maggots should be avoided, except for spot treatment or manure that is scheduled to be removed. This is especially so with products (e.g. pyrethroids, organophosphates) that will kill beneficial insects inhabiting the manure. Cyromazine and pyridine spot treatments of small areas with higher numbers of maggots can be effective and yet have a minimal effect on the beneficial insect population and potential fly resistance development in the manure.
Cyromazine (Larvadex) is the only feed-through insecticide for breeding flies registered for caged layers. It is an insect growth inhibitor and kills fly larvae before development is completed. Its selective mode of action does not adversely affect natural fly predators. Larvadex premix is blended in to the egg layer ration at the rate of 1 pound of premix per ton of feed for fly control. It passes through the bird’s digestive tract and is present in the manure essentially in its unaltered state. It has no adverse effect on feed palatability or consumption, or on eggs or meat.
Larvadex will give best results when integrated into a well-managed fly control program. Use of this product too frequently can be expensive. Also, where it has been used extensively, high levels of fly resistance have been reported. It is best to use Larvadex after a complete manure cleanout. After cleanout, it can be fed to the birds continuously for 4 to 6 weeks. Its use after that should be avoided until the next cleanout. This will reduce the chance of development of fly resistance. If adult flies should become a problem during its use or after the time it is used, then proper adult fly control measures should be carried out.
