Honey bees with roots in the local environment manage much better in the struggle for survival than imported honey bees from foreign environments, according to new research published in a special issue of the Journal of Apicultural Research.
Since 1886, queen bees have been delivered by mail to beekeepers and breeders. Today it is estimated that about one million queen bees are annually sent by mail, mainly in the USA, Canada, Europe, and Australia.
However, scientists from a half dozen European countries have found that bees that are adapted to the local environment fare much better than bees that have been purchased and imported from a completely different home area. They determined this by investigating the interaction between the genetic makeup of honey bees and their environment. Even though quite a lot is known about the geographical and genetic diversity of honey bees, knowledge of how honey bees adapt to the local environment has been limited.
“Many beekeepers believe that it is best to buy queens from outside instead of using the queens they have in their own beehives,” said senior scientist Per Kryger from the Department of Agroecology at Århus University. “However, there is increasing evidence that the global honey bee trade has detrimental effects, including the spread of new diseases and pests.”
The study was carried out by using 621 colonies of honey bees with 16 different genetic origins. The beehives were set up in 11 countries in Europe, with one local strain and two foreign strains of honey bees at each of the locations.
The factors that had the greatest influence on the survival of the bees were infection with Varroa mites, problems with the queens, and infection with the disease Nosema. Colonies with queens from the local environment managed on average 83 days more than colonies with queens from foreign areas.
“It is very clear that the local bees fare better than imported ones, and that they live longer,” said Dr. Kryger. “It is not possible to point at one single factor that gives the local bees the advantage, but it appears to be an interaction between several factors. Our results indicate that the way forward is to strengthen the breeding programs with local honey bees instead of imported queens. That would help maintain the bee population’s natural diversity. It would also contribute to preventing the collapse of bee colonies, optimize sustainable productivity, and make it possible to maintain continual adaptation to environmental changes.”
“Damage from importations may arise from accompanying pests and pathogens, but it is also inevitable that introduced bees represent a burden to the genetic integrity of local populations,” the authors wrote. “The spread of imported genes into the local population is likely, and the resulting increase in genetic diversity is not universally beneficial. Since maladapted genes will be selected against, this process may well in the short term contribute to colony losses, and is in the long term, unsustainable.”
The research was carried out by members of the international honey bee research association COLOSS that has members in 63 countries.
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