Dangerous Honeybee Diseases Jump to Wild Pollinators

Ever since it was first noticed in 2006 that America's honeybees were dying en masse, the spotlight has been on these essential pollinators. It was quickly revealed that not only US honeybees, but entire global populations were in trouble, with troubling declines in Europe and even Australia. Now a new investigation has revealed that a suite of diseases that once exclusively affected domestic honeybees has moved on to infect wild bees, such as the common bumblebee, as well.

That's at least according to a study recently published in the Journal of Animal Ecology, which details how multiple interconnected diseases that have long been battled and contained by beekeepers are suddenly showing up in wild bumblebee populations - where they will be much more difficult to manage.

"Our results confirm a recent review of potential threats to pollinators, indicating that so-called honey bee viruses are widespread in wild bees," researcher Mark Brown, from the Department of Biological Sciences at Royal Holloway, University of London, reiterated in a statement.

"It is imperative that we take the next step and identify how these viruses are transmitted among honeybees and wild bees," he added, "so that we can manage both to reduce their risk of disease."

The research identified five major viruses now present among wild bumblebees: black queen cell virus, deformed wing virus, acute bee paralysis virus, slow bee paralysis virus, and sacbrood virus - all of which are named after how they affect honeybees specifically. It remains unclear if they present the exact same symptoms in their new victims. (Scroll to read on...)

The diseases were also indentified among wild bees and managed honeybees near 26 sites across Great Britain, where some of the diseases remained more prevalent among domestic bees, while others had almost made a full jump to infecting mostly wild populations.

This suggests that some viruses are predominantly spread by honeybees, whilst others have 'learned' to rely on wild bumblebees. It also explains for increasing declines in bee populations across Europe, despite a 2-year-old moratorium in all European Union nations that has placed a temporary halt on neonicotinoid use until a final consensus on their threat and management is made this December.

As things stand, the scientific consensus remains that these pesticides, called neonics, can threaten both honeybees and wild bees alike, even while other factors like viruses, parasites, and climate change keep populations from recovering. In fact, one in 10 European bee populations are reportedly facing extinction. Now, even once-managed viral and parasitic diseases have to be added to that growing list of pollinator threats.

"Our findings are important because they indicate that many viruses can spread easily between pollinator species and, furthermore, that they can reach very high disease levels in wild bumblebees," said Dino McMahon, from Queen's University (QU), Belfast.

"Our previous research suggested that a key virus of the honeybee - deformed wing virus - spills over to infect bumble bees, probably via contact at flowers. We now find that other viruses may be doing the same," added Robert Paxton, a colleague of McMahon's. "Yet our new findings also highlight just how little we know of bee parasites and the role they play in the decline of pollinators."

The researchers hope to continue investigating these diseases and others, in the hopes of determining just how they will affect wild populations. In learning this, ways to help protect these essential creatures could also be determined.

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