The main cause of honey bees being endangered are parasites, including tracheal and varroa mites that were introduced into North America in the 1980s. These parasites cause diseases that can be harmful to the bees' colonies, such as a disease that causes newly raised bees to emerge with malformed wings and the inability to fly.
Although miticides have been developed that are effective against these mites, the mites are beginning to develop resistance to the chemicals, as of 2015. Scientists are developing a strain of mite-resistant honeybees in hopes of repopulating bees throughout the affected areas.
Other causes of decline in the population of bees is the deforestation and destruction of native habitats due to building of parking lots, shopping malls and other structures.