Honey Bee Mite

• GeneralThe leading cause of hive losses worldwide; it parasitises bee larvae.
• parasitismoIt is an external parasite of honeybees that feeds on their fat body and can pass on viruses, and is one of the main factors in the worldwide decline of bee colonies.
• Its original host is the Asian honeybee Apis cerana, which has coevolved with it and keeps it in check; the jump to the European honeybee Apis mellifera in the twentieth century set off a global pandemic.
• For years it was believed to feed on haemolymph, but it has been shown to consume the fat body, the organ the bee needs to survive the winter and to detoxify.
• It is the single greatest cause of the worldwide decline in honeybee health.
• For fifty years it was believed to suck haemolymph, as a tick sucks blood. A 2019 study showed otherwise: it eats the fat body, a tissue equivalent to the mammalian liver, digesting it externally.
• That matters a great deal, because the fat body regulates hormones, the immune response, pesticide detoxification and winter survival. It explains the range of damage that simple loss of haemolymph could not account for, and why some treatments failed.
• Mites fed haemolymph in the laboratory lived no longer than those given nothing at all; those fed fat body lived longer and laid more eggs.
• It jumped from the Asian honeybee, Apis cerana, to the European one in the early twentieth century, and with it came a direct route for inoculating viruses into the bee's body, above all deformed wing virus.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat and environment

Honeybee hives

Sources consulted: Wikipedia (es): Varroa destructor · ScienceDirect (Hughes 1989) · Science Advances, How colonial animals evolve · Wikipedia, Zooid