London, Feb 7 (IANS): Humans are responsible for the spread of a virus that is killing global bee populations, a new research has found.

The populations of European honeybee called Apis mellifera is the prime source of the Deformed Wing Virus, and human trade and transportation of bees for crop pollination is driving its spread, according to researchers at Britain's University of Exeter and UC Berkeley.

Although separately they are not major threats to bee populations, when the Varroa mite carries the disease, the combination is deadly, and has wiped out millions of honeybees over recent decades. Varroa feed on bee larvae while the Deformed Wing Virus kills off bees - a devastating double blow to colonies.

"This is the first study to conclude that Europe is the backbone of the global spread of the bee killing combination of Deformed Wing Virus and Varroa," said study lead author Lena Wilfert from the University of Exeter.

"This demonstrates that the spread of this combination is largely manmade. If the spread was naturally occurring, we would expect to see transmission between countries that are close to each other, but we found that, for example, the New Zealand virus population originated in Europe," Wilfert added.

Researchers said that moving animals and plants around the world could have devastating consequences both for domestic animals and for wildlife.

"The risk of introducing viruses or other pathogens is just one of many potential dangers," said Roger Butlin, professor of evolutionary biology at the University of Sheffield.

The study findings were recently published in the journal Science.