|A new type of virus threatens the health of bees around the world|
A dangerous variant of the deformed wing virus is spreading throughout the world. Honeybees are infected by the virus, which causes their wings to atrophy and the animals to die.
The new strain of the virus, which has already replaced the original strain in Europe, is spreading to other parts of the world and causing entire bee colonies to die. This was demonstrated in a study led by Martin Luther University Halle-Wittenberg (MLU) that examined data on the spread of virus variants over the last 20 years. The study was published in the International Journal of Parasites and Wildlife.
The parasitic Varroa mite transmits the deformed wing virus (DWV). "These mites not only transmit viruses between honeybees, but they also eat the bees' tissues," explains MLU bee researcher Professor Robert Paxton.
For many years, he has been researching the spread of various pathogens in honeybees and wild bees. "The most serious threat to honeybees is definitely deformed wing virus," Paxton adds. The virus's original strain ("DWV-A") was discovered in Japan in the early 1980s, and the new variant "DWV-B" was discovered in the Netherlands in 2001. "Our laboratory studies have shown that the new variant kills bees faster and spreads more easily," Paxton says.
The zoologist-led team wanted to know how common the new variant has become in nature. To determine this, the researchers examined approximately 3,000 datasets from the NCBI database for honeybees, large earth bumblebees, and Varroa mites. The datasets contain information about the viruses' genetic material. They also looked for the first scientifically documented references to the "DWV-B" variant in a variety of countries.
"Our analyses show that the new variant has already gained a foothold in Europe and that it will only be a matter of time before it becomes the dominant form worldwide," Paxton says. In the 2000s, the new variant was mostly found in Europe and Africa, the honeybee's native habitat. It was discovered in the early 2010s in North and South America, and in Asia in 2015.
With the exception of Australia, the virus variant has now been detected on all major landmasses. According to the researchers, this could be due to the Varroa mite's inability to spread widely there.
The virus was also discovered in samples taken from large earth bumblebees. "It is unclear whether the virus will have the same devastating effects on bumblebees and other wild bees.
So far, infected commercial bumblebee colonies are not dying at a significantly higher rate "Paxton says There are several methods for protecting honeybees from the Varroa mite and virus: "The most important thing to remember is to keep the hive clean. Simple precautions can help to protect not only one's own colony from Varroa but also wild bees that no one else is watching over "Paxton wraps up.
Honeybees, as pollinators of many wild and cultivated plants, play an important role in fruit yields and biodiversity conservation. Experts all over the world are concerned about the loss of honeybee colonies.
Materials provided by Martin-Luther-Universität Halle-Wittenberg. Note: Content may be edited for style and length.
Robert J. Paxton, Marc O. Schäfer, Francesco Nazzi, Virginia Zanni, Desiderato Annoscia, Fabio Marroni, Diane Bigot, Eoin R. Laws-Quinn, Delphine Panziera, Christina Jenkins, Hassan Shafiey. Epidemiology of a major honey bee pathogen, deformed wing virus: potential worldwide replacement of genotype A by genotype B. International Journal for Parasitology: Parasites and Wildlife, 2022; 18: 157 DOI: 10.1016/j.ijppaw.2022.04.013