Local honey bees have higher survival chances

Honey bees with roots in the local environment manage much better in the struggle for survival than imported honey bees, a new study has found.

Scientists from Aarhus University in Denmark and colleagues found that bees that are adapted to the local environment fare much better with regard to meeting the challenges than bees that have been purchased and imported from a completely different home area.

The scientists 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.

However, there is increasing evidence that the global honey bee trade has detrimental effects, including the spread of new diseases and pests, said senior scientist Per Kryger from the Department of Agroecology at Aarhus University.

Researchers carried out studies in 621 colonies of honey bees with 16 different genetic origins. The beehives were set up in 11 countries in Europe. There was 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 queen, 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 Per 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, Per Kryger said.

"Our results indicate that the way forward is to strengthen the breeding programmes with local honey bees instead of imported queens. That would help maintain the bee population's natural diversity," said Per Kryger.

"It would also contribute to preventing the collapse of bee colonies, optimise sustainable productivity, and make it possible to maintain continual adaptation to environmental changes," Per Kryger added.

The results of the project are reported in the Journal of Apicultural Research, published by the International Bee Research Association.