How feral colonies fare with Varroa

Feral honeybee colony. Photo: Julie Lake.

Could feral colonies be a reservoir for varroa-tolerant bees? New research in Plos One suggests not. Abandoning Varroa treatment could leave colonies dangerously exposed, say  the researchers.

Anecdotal reports have spoken of a recent resurgence on feral honeybee colonies and the hope that they may be resistant to Varroa, but new research does not support those hopes.

It indicates that feral colonies in the UK have similar profiles of viruses to managed colonies, and that the feral colonies contained a significantly higher level of Deformed Wing Virus (DWV), the virus that is often lethal to the colony.

Rather than being a distinctive genetic group of honeybee colonies, the research thought that the feral colonies were probably simply escaped swarms from managed colonies. Untreated « managed » colonies closely resembled the virus profile of feral colonies in many ways.

The researchers gave a stark warning about not treating for varroa:

« A workable level of Varroa tolerance is keenly sought by UK beekeepers, but abandoning Varroa treatment without ensuring colonies have evolved a natural resistance to the mite, or without virus-free Varroa, could leave colonies dangerously exposed, particularly in areas of high beekeeping density. »