Bloodsucking Parasite Threatens UK Honeybees

Scientists at the University of Warwick have discovered how a bloodsucking parasite has transformed Deformed Wing Virus (DWV) into one of the biggest threats facing UK honeybees.

The findings were published in the journal PLOS Pathogens.

Honeybees are a key pollinating insect - adding a $40 billion global crop value - but now emerging threats are putting increasing pressures on these insects, as well as the agricultural industry.

Over recent years the spread of parasites and the viruses they transmit has resulted in high overwintering colony losses. DWV is one of the most common of these viruses, affecting all European honeybees. Although present in most colonies, high levels of the virus - characterized by developmental deformities, reduced foraging ability and longevity - only run rampant when Varroa destructor is also present.

This tiny parasitic mite invades hives across the globe, feeding on honeybee blood. In colonies free from Varroa, DWV is present at very low levels and generally causes symptomless infections. However, the research team found that when Varroa is present, specific virulent strains of the virus are transmitted and amplified, explaining why colonies infested with the mite suffer most severely.

And by directly injecting a mixed DWV population in the absence of the mite, which resulted in the same destructive virulent strain, researchers also showed that the virus can bypass the insect's anti-virus defense systems.

"Although exposure to Varroa caused disruption to a number of genes involved in the bee's immune response, it is the route of transmission which has caused this severe strain of DWV to become widespread," study leader Professor David Evans, from the University of Warwick, explained in a statement.

Researchers hope that by identifying the threat this virus poses, they can soon implement strategies to combat its effects.

"The identification of a single virulent form of the virus is an important step in developing strategies to boost honeybee health, to prevent colony losses and to safeguard this important pollinator," Evans added.

And like the United Kingdom, the United States is also grappling with the mass loss of honeybee populations, and pesticides are likely to blame for their decline.

President Barack Obama just announced his plan to save these honeybees by creating the Pollinator Health Task Force, responsible for addressing the issue and coming up with a solution.