What mite is a major parasite of honey bees?

The mite that is a major parasite of honey bees is Varroa destructor.

Varroa destructor is an external parasitic mite that attacks both developing and adult honey bees. It is especially damaging to the western honey bee, Apis mellifera, which historically lacked the long co-evolutionary relationship seen in the mite’s original Asian host, Apis cerana. Heavy infestations weaken colonies and can lead to collapse.

The mite reproduces inside capped brood cells, with drone brood often preferred. Adult female mites then ride on adult bees in a dispersal stage, moving through the colony or between colonies. Modern research shows that Varroa feeds primarily on the bee’s fat body tissue rather than simply drinking hemolymph, weakening systems involved in energy storage, immunity, and development.

Varroa is also a major vector of damaging bee viruses, including deformed wing virus. This makes it more than a nuisance parasite: it amplifies disease and contributes to serious losses in managed and wild bee populations. A major taxonomic mix-up lasted until 2000, when DNA and other evidence showed that the destructive mite long called Varroa jacobsoni was actually a separate species, Varroa destructor.