Red mites, also known as poultry mites, roost mites, chicken mites, and, scientifically, as Dermanyssus gallinae, are ectoparasites (which means that they live and feed on the exterior of a host) that affect poultry, as well as other species of birds, such as pigeons, sparrows, doves, starlings, etc. They are considered to be arachnids, not insects. They should not be confused with red spider mites (Tetranychus urticae), which are parasites that live in gardens and affect certain plants, and they are generally considered to be harmless in comparison with other species of mites, or with northern fowl mites (Ornithonyssus sylviarum), another arachnid that affects birds and that is abundant in the United States. Red mites are distributed worldwide, being most prevalent in European countries.
Description and distribution
A typical red mite is white, light yellow, or light grey in colour, becoming darker and closer to a shade of red as it fills with the blood that it has consumed. It has an oval-shaped, eight-legged body and measures around 0.7-1 mm, being just barely large enough to be spotted without magnification. They have no wings and no obvious body segmentations.
Poultry mites are distributed worldwide, and in many countries, Dermanyssus gallinae poses a threat to birds used for meat and egg production. They are found in many areas including Europe, Japan, China, and the United States, and can live in a variety of cracks and crevices, in bird nests, under dirt or manure, being most common in hen houses, seeing as that is where food is most easily accessible to them. They feed at night and, once they do, they hide, away from daylight (which they hate), mating and eventually laying eggs. Thus, unlike other species, they do not spend their entire lives on a single bird, but can only be found on one during active feeding periods.
Breeding and dietary information
A mite’s life is composed out of 5 main stages: egg, larvae, protonymph, deutonymph, and adult. Eggs hatch in 2 – 3 days, becoming six-legged larvae; these moult in 1 – 2 days, giving rise to eight-legged protonymphs, which, in turn, feed and turn into eight-legged deutonymphs. If the environmental conditions are favourable enough, the transition from egg to adult may be easily completed within 7 days. Populations, therefore, grow very rapidly. Red mites start feeding only once they have passed the larvae stage. They feed mainly on blood, but they can consume all parts of a chicken, including feathers, skin, and scales. They usually feed between 1-2 hours each night, but they can survive without food as long as 8 months, which causes them to be very difficult to remove completely.
Poultry red mites as pests
Because they feed on blood, red mites attack birds, normally at night, around the breast and leg areas, causing pain, irritation, scabs, etc.; pustules, hyper-pigmentation, feather loss, extreme stress, and a decrease in egg production (particularly where hens are concerned) are also associated consequences and conditions. In the case of very severe infestations, red mites can lead to anaemia, especially in younglings, and the health of birds can also be affected by these parasites indirectly, seeing as they are proven carriers of diseases such as Salmonellosis, Avian spirochaetosis, Rickettsial pox, Scrub typhus, Mange, Scabies, Dermatitis, Pruritis, Tsutsugamushi, Erysipelothrix rhusipathiae, etc.
Although they are incapable of living and reproducing on human hosts, red mites are also known to bite humans (especially if they enter an infested hen house at night) and other species of mammals (such as pets), causing pain and possibly irritation, itchiness, and even dermatitis and skin lesions in sensitive individuals. Considering this, it is no surprise that red mites are considered to be serious pests, mainly because they are a threat to birds that are used in meat and egg production, but also because they produce uncomfortable symptoms in people that come in contact with them.
You can easily figure out if your chickens are dealing or not with red mites if you observe their behaviour. As the mites usually attack at night, as they stay hidden in the chicken coop during the day, you will notice your hens and roosters being reluctant to enter their coop to sleep. Hens can also stop using their nesting boxes as those can get easily infested as well. Another clear sign of infestation will be the scales on the legs of birds. If they are beginning to lift up and have a paler colour, it is a sign that mite waste is building up underneath them. This will also become painful and debilitating to the birds, and adding this to the constant state of itchiness, their life will become a very stressful one, which will also affect their egg production. Dirty looking feathers, a pale comb and a sudden decrease in weight are also visual signs that the health of your birds is heavily affected.
Treating the chicken coop is half the solution, as the birds also need to be taken care of at the same time. For treatments on the chicken coop you will need to take time and strip it apart as much as you can, and apply insecticides specifically meant for mites only after. When treating the chickens, you can rub Diatomaceous Earth on their feathers, but also use wood ash, or mixtures of water and garlic oil, neem oil, or others such as lavender, cinnamon, spearmint, bay or thyme.
It’s important to also know how to prevent such infestations from happening. Good sanitation practices, frequent flock inspections and ample access to dust bathing surfaces can keep your chickens free of red mites. A good feeding plan will also keep your chickens safe, as mites prefer to attack already weaker birds. Keep your coop clean and make sure you check it regularly, feed your chickens properly and make sure to keep in check the contact they have with any other wild birds that might spread these parasites.
For more details on ways in which you can ‘Prevent infestation with Poultry Red Mites‘ or ‘How to get rid of Poultry Red Mites‘ infestation, you can check our relevant articles.