Varroa Orthomyxovirus-1 in Varroa mite

Honey bees are increasingly threatened by the Varroa mite (Varroa destructor). This mite is an external parasitic mite that attacks and feeds on honey bees, and is one of the most damaging honey bee pests in the world. A significant mite infestation leads to the death of a honey bee colony, usually in the late autumn through early spring. Without management for Varroa mite, honey bee colonies typically collapse within 2 to 3 years in temperate climates.

[The dreaded Varroa mite]

These mites can infest the western honey bee (Apis mellifera) and the Asian Honey bee (Apis cerana). Since it is very similar physically to the closely related Varroa jacobsoni, these species were thought to be one prior to 2000, but they were found to be two separate species by DNA analysis.

But the Varroa mite itself is infected by several virusses.

Research showed that a novel orthomyxovirus was present in both the Varroa mite and its preys, the western honey bee and Asian honey bees[1]. The researchers found evidence for viral replication in both hosts. The novel orthomyxovirus was provisionally named Varroa orthomyxovirus-1 (VOV-1).

Varroa Orthomyxovirus-1 showed 23 to 58% homology to the Orhomyxoviruses Thogoto and Dhori, which bear negative-sense single stranded RNA genomes of six segments.

Later, the name of the virus seems to have (needlessly) changed to Apis orthomyxovirus 1[2]. Which strange, because the mite has infected the bee.

So, again an unknown Orthomyxovirus has been found that is a relative of the Influenza viruses. It again increases the risk of jumping species, and becoming a menace to humans. Nature remains unpredictable and we do not know which undetected viruses lurk where.

[1] Levin et al: New Viruses from the Ectoparasite Mite Varroa destructor Infesting Apis mellifera and Apis cerana in virusses – 2019. See here.
[2] Deboutte et al: Known and novel viruses in Belgian honey bees: yearly differences, spatial clustering, and associations with overwintering loss in Environmental Microbiology - 2024. See here.