Skip to main content
European Commission logo
English English
CORDIS - EU research results

Article Category

Content archived on 2023-04-17

Article available in the following languages:



Everyone has long known that in order to prevent swarming of a colony of bees, it is necessary to expand their nest, giving them more space and extra work. If this event is carried out on time, then the swarming state of the family may fade away. But what is even more interesting is that such a solution of the swarming problem can drastically reduce the rate of development of Varroa mites in the bee colony. What is the reason for this?

Climate Change and Environment icon Climate Change and Environment
Food and Natural Resources icon Food and Natural Resources
Fundamental Research icon Fundamental Research

The fact is that at the beginning of the process of preparing for the swarming, the task of the family and the queen is to build up the maximum possible strength of the family before the swarm leaves. Then, dividing in two, the family will remain large enough to survive and collect honey for the wintering. To do this, the queen begins to fill all the cells in the hive suitable for this with brood ... But the nest is not the whole hive, and the bees do the following!! They start powerful heating of the ENTIRE hive! The whole hive turns into a nest! This event in the life of a family of bees becomes the "golden" time for Varroa mites and the cause of the subsequent troubles of bees ... down to their death .... Now the mites can actively reproduce in a huge amount of brood, and not only in brood of worker bees, which used to be warm enough even earlier, but also to reproduce actively in drone brood... This at least doubles their breeding potential, which ultimately leads to exponential growth of the mite's population in April-June. Such a leap in the growth of the mite's population occurs primarily in the families, which are initially ready for swarming - that is, in the families with old queens. It is possible that this was the reason for the confidence of many beekeepers that bee families with young queens are better able to cope with the mites. But it is a normal thing, in the families with young queens, bees are less prone to swarming, which means that they are less prone to heating the entire hive and to the massive construction of drone cells, which become a "bomb" placed under the colony during swarming time. Based on this, the maintenance of the families with young queens is one of the important elements of the fight against Varroa mites without the use of poisonous chemicals. Here, the most important thing is not even the age of the queen, but the moment of the beginning of pre-swarming state of the bees... even if the queen will not lay eggs in new queen cells, the behavior of the bees themselves - preparing a place for unlimited oviposition, building of drone cells and powerful heating of the entire hive - leads to fatal consequences. In addition, multiple growth of the mite's population occurs with the participation of drone brood. So, installation of building frames and removal of sealed drone brood is also a good method for reduction of Varroa mite's population without any use of poisonous chemicals. And finally, the most important thing for saving bees is expanding the nest with new honeycombs or body-boxes ... What is the reason for the effect of this method on the bees, preparing for swarming, or on their new and big nest? If the bees are unable to eliminate the consequences of our actions and maintain the heat balance, necessary for normal swarming, then, apparently, they postpone swarming indefinitely! And they stop trying to heat the enlarged hive. In this case, the family returns to the normal life cycle, not associated with swarming ... For Varroa mites, this means not only the inability to fully utilize the drone brood, but also the inability to use more brood of worker bees ... The mite's population growth will no longer be exponential and the bees will have more chances of survival, and the beekeeper will get marketable honey. As a result, it becomes clear, that beekeepers must apply all possible methods, leading to the fact that swarming mood of the bees will not develop further, or will be completely suppressed ... These are: a young queen, installation of building frames, removal of drone brood, and especially - expansion of the nest! Significant expansion of the nest or installation of additional housing and transfer of part of the brood into it during the pre-swarming time will not only stop the swarming process, it will also deprive the bees of the opportunity to heat the entire hive and to create an "incubator" for Varroa mites in a well-heated drone brood.