The European Commission calls Epilobee "the biggest research ever done into the deaths of bee colonies". Winter deaths in 2012-2013 were particularly high in Belgium (33.6 percent) and the UK (19 percent).
The study shows a clear difference between southern Europe and the northern countries. Greece, Italy, Spain, Hungary and Slovakia had a death rate below 10 percent, which is considered as normal. At the same time, Denmark, Sweden, Finland, Estonia, Belgium and the UK exceeded the threshold of 20 percent.
Bees play a crucial role in the pollination process. Last year, the European Commission decided to ban 4 types of pesticides that may be responsible for the high death rates. However, the debate of the cause of death is still ongoing.
The investigation involved 32,000 domesticated colonies, but did not include wild bees and bumblebees. The situation of these last two categories gives even more rise for concern, experts say.