Bee colonies are threatened by a new variant of a dangerous virus. A team of international scientists discovered a worldwide increase of a new variant of the dangerous deformed wing virus (DWV) that infects honeybees. Transmitted by the Varroa mite, the virus causes a degeneration (atrophy) of the wings that results in death. The Varroa mite is one of the biggest threats for honeybees.
In Europe, the new variant has already replaced the original strain of the virus. It is spreading worldwide and causes entire bee colonies to collapse. The researchers at the Martin Luther University Halle-Wittenberg (MLU), analyzed 20 years of data on the spread of virus variants.
The leader of the study, Professor Robert Paxton, explains,
“These mites not only transmit viruses between honeybees, they also eat the bees’ tissues. Deformed wing virus is definitely the biggest threat to honeybees. Our laboratory studies have shown that the new variant kills bees faster and is more easily transmitted.”
Researchers in Japan discovered the original strain of the virus (“DWV-A”) in the early 1980s. The new variant “DWV-B” was first identified 21 years later in the Netherlands.
Paxton and his team wanted to investigate how widespread the new variant has become in nature. For this, the researchers evaluated about 3,000 datasets for honeybees, large earth bumblebees, and Varroa mites from the database NCBI. They investigated the genetic material of the viruses and the scientifically documented references to the “DWV-B” variant for numerous 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 is the dominant form around the world.”
In the 2000s, researchers detected the new strain in Europe and Africa. Both continents are the homeland of the honeybee. Furthermore, the new strain spread to North and South America in the early 2010s , and subsequently to Asia by 2015.
According to scientists, the new variant of the dangerous deformed wing virus is currently present on all major landmasses at present. The only continent that remains unaffected so far is Australia. The scientists believe this is because the Varroa mite is not yet widely spread there.
The researchers also found evidence of the virus in samples taken from large earth bumblebees.
”Whether the virus will have similarly devastating consequences in bumblebees and other wild bees remains uncertain. So far, commercial bumblebee colonies infected with the virus are not dying at a significantly higher rate.”
Honeybees can be protected from the Varroa mite and the virus in various ways. Paxton concludes,
“The most important thing is to pay attention to hygiene in the hive. Here, simple measures can help to protect not only one’s own colony from Varroa, but also wild bees that no one else is looking after.”
Honeybees play a vital role in pollinating plants that are necessary for the survival of the human race. Honeybees preserve biodiversity on our planet, and experts around the world are concerned about the loss of honeybee colonies. The study is published in the International Journal for Parasitology: Parasites and Wildlife.
Story Source: Materials provided by Martin-Luther-Universität Halle-Wittenberg. Note: Content may be edited for style and length. Journal Reference:
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
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Martin-Luther-Universität Halle-Wittenberg. "New virus variant threatens the health of bees worldwide." ScienceDaily. ScienceDaily, 1 June 2022. <www.sciencedaily.com/releases/2022/06/220601111805.htm>.