Over the winter of 2018/2019, 13.6% of bee colonies dwindled in Switzerland. In addition, 12.1% of colonies were too weak after the winter to develop into worker colonies.
The hot summer of 2018 confused the beekeeping calendar. The fight against the Varroa mite was not as effective for a while due to the high daytime temperatures. A very late regional honeydew flow caused the bees additional stress. So, many beekeepers expected higher losses over the winter. In fact, at 25.7%, the loss is about 2.5 percentage points higher than the previous year, but still mediocre in comparison to the last ten years.
This was the outcome of the Apisuisse annual survey of 1,246 beekeepers across Switzerland, who looked after a total of 20,000 bee colonies in 1908 apiaries before last winter.
There are great differences between cantons. At altitudes over 1000 meters, it is a known fact that the strain placed on bee colonies by the Varroa mite is lower than in the central
plateau, which could explain the lower levels of loss in the mountainous cantons.
Based on AvS
Translated by Justine Hewson