Fly control is a major concern in poultry production, especially in commercially grown caged layer houses. The shift from many small farm flocks to fewer large poultry operations has greatly increased fly problems by creating concentrated breeding areas and large volumes of waste that cannot be removed frequently. As urbanization and rural non-farm residences increase, poultry producers face increasing pressures to reduce / control fly population. Fly control in caged layer operations is difficult and requires an integrated approach using proper manure management, enhancement of populations of biological control agents (fly predators and parasites), and selective use of insecticides.
Several kinds of flies are common in and around poultry houses, most common flies are the house fly and the little house fly. About 95% of problems involve the house fly.
The types of flies are 1). House fly, 2). The little house fly, 3). The black garbage fly and 4). Blow flies.
The house fly, Musca domestica L., is the major fly species associated with caged layer
houses and are known vectors of >100 pathogens such as protozoa, bacteria, helminthes, and viruses. House flies are also mechanical vectors of zoonotic diseases on poultry e.g., Campylobacter, Salmonella, and avian influenza. It breeds in moist, decaying plant material, spilled grains, spilled feed and all kinds of manure. As these conditions are
prevails around the poultry houses, house flies are common to find and flies prefer sunlight and very active, crawling the fith.
Little house fly, Fanniacanicularis (L), is smaller than the house fly.
This fly prefers a less moist medium than house fly for breeding and reproduction. It prefers manure, shade and cooler temperatures and is often seen in feed room, egg storage and poultry house.
Black garbage fly, Ophyraaenescens, is smaller than house fly in a bronze brown shiny colour. The wings are held straight back. This fly prefers to stay on the food source at night rather resting on ceiling.
Blow flies, also known as green / bluebottle flies and larger than house flies. They prefer to breed and reproduce in decaying animal
and bird carcasses, broken eggs and wet garbage.
Fly biology: Understanding their life cycle biology helps to control flies effectively in poultry houses. All flies develop through four life stages: egg, larva, pupa and adult. Most adult flies lay small, white, oval eggs on the breeding medium. Creamy white larvae (maggots) develop in moist materials. Mature maggots crawl out of this material and move to a drier place for the pupal stage. The brown, seed-like pupae finally yield adult flies. Development from egg to adult fly may take just 7 to 10 days under the ideal conditions.
Control methods: Appropriate sanitary and management practices should be included in layer and breeder poultry operations to control house fly, little house fly and other flies to reduce their number and size of breeding sites.
CULTURAL CONTROL:
Manure management is the most effective way to control fly population. As fresh poultry manure contains 70 – 80% moisture, it makes ideal for fly breeding. Flies practically eliminated by reducing the moisture content of manure to 30%. Drying is preferred as it occupies less space and have less odor.
Manure management:Frequent manure removal at least once a week if possible prevents fly breeding because it breaks breeding cycle. But because of large poultry flock sizes (layer / breeder) and limited land availability it is difficult to remove manure on weekly basis. Scattering manure lightly outdoors to helps in killing the eggs and larvae by drying. Any practice that limit the moisture in the droppings or reduces close to 30% level aids in fly control.
Water management:the following steps of managing water content of manure can control flies. a) Prevent leaks through drinkers / nipples, b) Regulating water flow through the pipes c) Provide abundant cross ventilation beneath cages, especially during hot weather.d) usage of fans blowing across the manure can be effective, e)ventilation in house & beneath cages is the key to manage manure moisture. If there is a danger of water running into the house from the outside, adjust floor height so that house floor is higher than the surrounding ground outside.
SANITATION:Sanitation is most important in successful fly control.Quickly remove & dispose dead birds and broken eggs. Cleaning of feed spills and manure spills immediately, cleaning of choked drains. Minimize the migration of flies from other fly-infested animal houses close to the poultry house.
BIOLOGICAL CONTROL:
Fly-parasites:In biological control, only beneficial insects are adapted. These fly-parasites are tiny wasps, naturally occurring enemies of manure-bedding flies. They destroy pupal stages of flies. These wasps are Spalangianigroaenea, Splangiacameroni, Spalangiaendius and Muscidifurax raptor, live in the manure, adult wasp fly deposits eggs in the fly hard coat of fly pupa. The developing wasp larva consumes the pupa and emerges as an adult. However, these wasps lay lesser number of eggs compared to breeding flies, need mass number of releases to control the flies through this method.
Fly-predators: It includes, mites and beetles in the manure, which are major predators in caged layer operations. The macrochelid mite, Macrochelismuscaedomesticae,it feeds on house fly eggs and first-instar larvae. This is found on outside layer of manure, can consume upto 20 house fly eggs per day. Carcinopspumilioand Gnathoncusnanus are beetles,lives in surface layers of manure, can consume 13 to 24 house fly eggs per day. These beetles occur in low numbers in poultry manure.
Using fly parasites and predators for biological control would reduce chemical residues to people, birds, eggs and the environment.
MECHANICAL CONTROL:
These are fly traps usually electrical with a charged grid to kill the insects. This kind of traps are helpful in tight, enclosed areas such as egg rooms. However, in areas of heavy fly population, traps are not effective in reducing the fly numbers.
CHEMICAL CONTROL:
Insecticides should be considered supplemental to the sanitation, and management measures must be directed to prevent fly breeding. The use of variety of different classes of insecticides on rotation basis can minimize the development of resistance.
Residual sprays:Residual sprays are the most effective and economical method for controlling the fly population of adult flies of any species. These sprays should be applied in spring at the beginning of the fly season and there should be a second application with a gap of 5-6 weeks. Targets for the spray are the surfaces on which flies locate, such as house framework, ceiling walls, trusses, wires supporting cages, electric light cords, house openings and shrubs and plants also be sprayed.
EC – Emulsifiedconcentrate;WP – Wettable powder
Low pressure sprays are applied at pressures of 5-6 kg/cm2, using a power or good proportioned-type sprayer. Treated areas may remain toxic for 2 – 15 weeks. Contamination of feed, water, and eggs should be avoided and never be sprayed on birds.
Foggers& Misters:
The residual sprays i.e. permethrin, others are sprayed as foggers and mist which provides a quick fly knockdown effect. Spraying micron particle sized droplets, is a very effective application with less or no residual effect. For indoor application to kill flies, windows and doors are closed.Pyrethrins are used at 1%, 1 ml per m2space is required. Spray directed towards upper areas of the room with room closed for at least 1 hour and ventilated before re-entry.
Building automizers:
These are used in closed egg rooms or other work areas where there is little or no air movement.0.06% to 0.1% pyrethrins + piperonyl butoxide can be used as a mist or fog in the air throughout the poultry house at the rate of 0.5 litre per 1000 m3 area as needed.
Suggested example protocol for insecticide fly control:
BAITS:
Baits are supplemental to residual and sprays. Baits are placed outside the cage house in the high rise cage house. These are selective adulticides suppress low fly population. Birds should never be accidentally eaten by the birds or mixed into feed. Methomyl, dichlovos, trichlorfon and tetra-chlorvinphos are mixed with sugar and coated ontoo strips.
Resin strips & fly belts: Ready to use dichlorvos 20% resin strips can be used at the rate of 35 strips per 1000 m3 enclosed area and replaced every 3 months.
Feed additive: Insectgrowth regulators (IGRs) known as Cyromazine, when blended into poultry feed, will control manure breeding flies in and around caged of layer and breeder birds. Cyromazine 1% premix kills fly larvae before the adult stage. It is added to feed at 0.05% (w/w) or 500 grams per ton. Cyromazine should never be fed throughout the year and monitor for resistance in large flocks.
- Adult flies are first monitored in and near the house. When the fly population is more and raises concern, a residual chemical such as permethrin is sprayed of fogged to control adult flies.
- Then manure is checked for maggot activity, if the maggots are active, cyromazine is introduced into feed. Cyromazine is continued for 4 – 6 weeks (4 weeks minimum), if little or no active maggots observed in the manure, cyromazine is discontinued.
EXAMPLES FOR CONTROLLING FLIES IN POULTRY OPERATIONS
Resistance and Rotation: Unfortunately, overuse of popular insecticide products over the years has led to the development of resistant fly populations. Rotation of the product used can help reduce the likelihood of resistance emerging. When rotating products changes should be made on the basis of chemical class (e.g. organophasphate or pyrethroid) rather than the brand.
Precise use of insecticides can help to reduce the development of resistance, as well as reduce the cost of treatment. Overuse of insecticides in manure areas may kill helpful biological defenders against flies. An effective monitoring program can guide decisions about precise and prudentinsecticide applications.
Human Health Risks: Always read and follow the manufacturer’s instructions for safe handling and personal protection whenever handling insecticides. Have appropriate gloves, goggles, clothing, footwear, respiratory protection, and any other personal protective equipment (PPE) indicated by the chemical’s safety labeling. When in doubt, request an SDS (safety data sheet) from your vendor or supervisor.
CONCLUSION
Fly control is a daily activity in large layer facilities. Depending on season, fly numbers can reachcritical levels in a matter of days if adequate measures are not taken for prevention. Flies area major irritant to chickens, reducing fly numbers enhances bird performanceand improves food safety.
by Dr. K. Prashanth Kumar, M.V.Sc & Ph.D (Poultry Science), Assistant Professor, Dept. of Poultry science, CVSc, Mamnoor, PVNR TVU & Dr. A. Ajay Kumar, BVSc & AH, Skylark Hatcheries Pvt Limited
