Acariosis is a disease of honeybees caused by the tracheal mite Acarapis woodi. Tracheal mites infest the tracheal system of the adult honey bee. They puncture the wall of the trachea and suck the hemolymph of the bee. Tracheal mites live, breed and lay eggs in the tracheal system. The adults and eggs plug the tubes of the trachea and spread secondary diseases and pathogens. The mites can’t be seen with the naked eye.
The symptoms often don't become apparent until there are high levels of infestation of tracheal mites in the hive. Once high numbers of mite exist, bees will show symptoms of crawling on the ground, in the hive, or up blades of grass, unable to fly. Their wings may be disjointed at odd angles on one side---appearing to form the letter 'K'. The condition is named after this symptom, and is known as 'K-wing". Honey production may be reduced when over 30 percent of the population is infested with tracheal mites.
Levels of tracheal mite infestations are highest in spring and fall when mite populations reach their peak. Colonies are slow in population build up in the spring and lack vigor. In the fall, a higher than normal proportion of the bee population dies before the onset of winter. Colonies show variability in their sensitivity to tracheal mites. Some colonies are resistant and unaffected by tracheal mites, while other colonies may be severely affected and collapse.
TransmissionMites are transmitted from bee to bee within a colony and to other colonies by robbing or drifting bees.