Poultry mite can be a serious problem to poultry keepers if not detected early enough. Poultry mites feed on fowl blood and can rapidly cause heavy losses owing to their very short life cycle which allow quick multiplication and heavy infestations. Birds become badly anaemic and fall ill or get infections caused by bacteria and viruses.
These bacteria and viruses can also be passed on to poultry keepers infecting them with dangerous diseases. The mite also causes blood spotting on eggs, making them unfit for sale.
While there are many species of poultry mites, many of these species are identical and readily infect birds. Mites are very small rounded shaped arachnids just visible without magnification. They are wingless and adults have eight legs without any obvious segmentation.
The lifecycle varies from 1 – 5 weeks. Eggs are laid on the host and hatch in a few days. The larvae moult once, twice or thrice depending on species in a further few days. One female may lay up to 90 eggs in her life. All eggs are laid on one host except Dermanyssus gallinae whose eggs are laid in suitable cracks or crevices and to which the nymph retreat to the birds to moult between blood meals. With such a short life cycle enormous population can be built up quite rapidly.
Mites are able to live away from the host bird for a sometime but cannot survive for long. This way they can be transferred between flocks through poultry handling equipment like crates, or clothing, wild birds and rodents.
The presence of mites is indicated by itching, irritation of the skin and dermatitis in various forms. Three types of poultry mites are of special importance.
Also referred to as gray mites and roost mites, the red mite (Dermanyssus gallinae ) is about 1.5mm long. It is a nocturnal mite that sucks the blood (turning its color to red) from the birds at night and hides in cracks and crevices on the roosts, walls, ceiling, and floors, under clods of dirt or manure or in nests during the day. Hens setting on eggs may be attacked during daytime. The lifecycle takes a minimum of 10 days, and there can be a massive build up leading to death through loss of blood in affected birds. Laying birds may refuse to lay in nests that are infested with red mites.
Often found in small, non-commercial poultry flocks they are most prevalent in breeder operations or poultry houses where birds are maintained on litter or have nest boxes. They have a preference for chickens as their host, but also attacks pigeons, cage birds and wild birds. They are known to carry Borelina anserine, the cause of spirochaetosis and also been known to carry the virus that causes equine encephalomyletis.
The tropical fowl mite
Liponyssus bursa also called Ornithonyssus bursa lives on blood of chicken, turkey, pheasants and other birds in many parts of the tropics. However, these mites can live away from the host bird. It attacks humans but cannot survive more than 10 days away from birds. They are commonly spread through bird-to-bird contact and can be found on birds during daytime as well as at night in caged layer facilities and on range turkeys.
Most part of the life cycle which is usually less than one week, is spent on the host. Eggs are laid on the host or in the nest and hatch within 24 hours. Both eggs and mites are found in the fluff of the feathers, mainly near the vent. Infestation is usually patchy, a few feathers carrying hundreds of mites, while adjacent feathers are almost free. They suck blood thereby causing anemia in birds that are highly infested.
The scaly leg mite
The scaly leg mite (Knemidocoptes mutans) primarily remains on the host for its entire life cycle burrowing in scaled skin of feet and shanks of birds. Older birds are more vulnerable. Birds contact the pest through prolonged direct contact with infested birds and environs.
Birds exhibit brittle, flaky or powdery appearance on the legs.
Signs of mite infestation
- Darkening of the feathers on white feathered birds due to mite faeces
- Scabbing of the skin near the vent
- Mite eggs on the fluff feathers and along the feather shaft
- Clusters of mites around the vent, abdomen, tail, or throat
- Swollen and tender legs and feet with discharge or exudates forming under the scales
Controlling fowl mites
Correct identification of the specific mite is important in selecting the appropriate treatment and control methods.
- Examine birds at night for mites. Cracks and crevices in the surroundings should also be examined during the day for mites.
- Clean out the nesting places and the poultry building first, burn the litter and thoroughly apply insecticidal washes to the surroundings. This includes cleaning and disinfecting housing facilities and equipment between flocks.
- Check all new birds before they are brought on to the farm to make sure they are parasite-free.
- Do not use heavily infested poultry housing for some considerable time or not use at all for housing poultry.
- Reduce people traffic to and from housing facilities.
- Eliminate contact between flocks and wild birds.
- Impose a minimum quarantine period of 2 weeks for new poultry entering the flock. Physically examine and treat the birds if necessary during this time.
- Both the red and tropical mites can be controlled with dust of common insecticides. Application of nicotine to nesting places has been found to be effective.
- Treat the walls, floors, roosts, nest boxes, and the birds simultaneously with Carbaryl (Sevin) dust. Dust individual birds with Sevin by placing the bird into a bag containing the powder with the birds’ head out then rotate/shake the bag to completely cover the bird with powder. Repeat this every 2 weeks as needed.
- Apply wood ashes and diatomaceous earth on building and nests.
- Use natural enzyme-containing lice and mite sprays that are non-toxic such as Poultry Protector.
- Treat scaly leg mites by directly applying oil based products such as petroleum jelly on the affected legs once a day for at least two weeks. Warm soapy water can also be used. Gently scrape or rub off the dead scales and mites from the birds.