Tracheal mites, Acarapis Woodi, are microscopic organisms that live in the honeybee trachea. These parasites clog the breathing tubes of the adult bees, blocking oxygen flow and eventually killing them. Also called Acarine disease, the reduced oxygen affects the bee’s ability to fly and often results in a large number of crawling or dead bees outside the hive.
The tracheal mites spend their entire life cycle inside of the honeybee trachea, with the exception of when they are migrating between bees. In the trachea, the mites will pierce the wall with beak-like mouth parts in order to feed on the hemolymph (bee blood). The repeated piercings result in a breakdown of the trachea and provide an opportunity for bacterial infections. When an infected bee dies, the mites living in it will abandon their now deceased host.
The mites enter the trachea of a newly emerged bee one day of age or younger, and remain there as long as they and the unfortunate bee are both alive. A female tracheal mite will lay 5 to 7 eggs shortly after entering the trachea of a new host bee and she will continue throughout her life. The eggs will hatch in 3 to 4 days. As the number of tracheal mites increase, the mites clog the trachea, making it harder for the bee to breath. A young, newly mated female will emerge from the trachea in which she developed and climb to the tip of a body hair. As bees come in contact with one another, the mites attach themselves to the body hairs of a passing bee and enter the tracheae through the thoracic spiracles (tracheal opening). Younger bees (less than 9 days old) are the most susceptible.