Ever wondered how bees resist Varroa naturally?

January 25, 2023by fani

Check out this training done by WPII of SafeAgroBee PRIMA project explaining SMR and Recapping


The Varro destructor mite has been an increasing threat to the Apis mellifera honey bees, which causes many colony losses each year. Fortunately, honeybees have a wide range of immunity behaviors that can help them cope with predators like this one. In fact, there is an increasing number of colonies that show resistance to this infestation. In European honey bee subspecies usually 5-20% of the Varroa mites remain infertile after invading worker brood cells. In addition, some mites show a delayed egg laying in relation to the brood development. In the 1990s, scientists had identified high levels of non-reproduction as an inherited character of worker bees which they named “Suppression of mite reproduction – SMR”. High levels of mite resistance were achieved by strong selection for this trait locations.



Another means of resistance is believed to be what we call RECapping.
The bees can probably detect the mite-infested cells, the open the cell, and the varroa mite might escape or its reproduction is disturbed. The bees reseal the cell again. Interesting right?



In the training done by WPII in Croatia, on 16 December 2022, Marin Kovačić (member of SafeAgroBee) explained that in the past five years, there has been many promising studies on the SMR and recapping behavior and that there might be around ten recorded studies on it. These studies showed that all of the populations that are surviving without treatment, they are showing higher recapping behavior or SMR values compared to the control colonies.



The training was very interesting and practical, despite the fact that it was done via zoom!
Each participant was prepared and very attentive to the explanation and demonstrations.
Marin talked about SMR and recapping, while showing very fascinating videos, explaining the whole procedure. This training is not hard in what concerns knowledge, but it demands a lot of practice and skill. And there are a few basic steps that one must know, in order to evaluate reliably the reproduction of Varroa mites. The most important thing he said is to learn how to open the brood cells properly.



The training was held online this time, but it will take place in person in Croatia next year and everyone is excited! The brood samples are going to be collected and Marin will explain later on when it is best to collect them.


Stay tuned for upcoming events…

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