Dermanyssus gallinae, the poultry red mite, chicken mite or roost mite, is a major pest of fowl, pigeons, and other caged birds worldwide. A parasite especially common to poultry breeding and egg production operations, it is directly responsible for hundreds of millions of dollars in egg industry losses every year. Despite its common names, Dermanyssus gallinae can parasitize a wide range of hosts, including mammals. Infestation rates are often higher in less intensive farming systems, such as barns, free-range and organic farming because the environments provide more opportunities for the mite to evade chemical control measures.
Life cycle and appearance of Poultry red mite
Belied by its name again, the poultry red mite is only red following a recent blood meal, otherwise the mite appears white, grey or black. Adults are about 1 mm long (0.04 inches) and have long legs. They are typically nocturnal feeders and remain hidden during the day in cracks and crevices, nests, cribs and roosts, egg conveyor belts, cardboard boxes and transportation cages. They can occasionally be found in clusters.
Dermanyssus gallinae goes through five recognized life stages: egg, larva, protonymph, deutonymph and adult. After mating, female mites lay 4–8 eggs per day over a period of three days, taking a blood meal between each batch. Larvae resembling the adult but with only six legs emerge from the eggs after 13–51 hours and moult within 24 hours of hatching to become an eight-legged protonymph; the mites do not feed prior to reaching this stage. The protonymphs will feed once before moulting into deutonymphs, which in turn require a blood meal before maturing into the adult form. The poultry red mite can live between 5–17 days, depending on the temperature. Higher temperatures shorten the mite’s lifespan.
Dermanyssus gallinae causes both direct and indirect damage in poultry houses:
- The loss of vitality due to parasitism reduces hens’ production; and
- The mite can transmit several viral diseases (Newcastle disease paramyxovirus; St. Louis encephalitis virus; the Eastern, Western, and Venezuelan equine encephalomyelitis viruses; avian influenza A virus; fowl pox virus) as well as bacterial infections (Escherichia coli, Erysipelothrix rhusiopathiae, Pasteurella multocida, Salmonella gallinarum and S. enteritidis).
Flocks with mite infestations can suffer from:
- visible skin irritation and lesions on the breast and legs;
- increased stress;
- altered sleep patterns;
- feather plucking;
- anemia, which presents as comb and wattle pallor; and
- death, in extreme cases.