3. Isolation with 3 km distance to other bees
Especially in the difficult year of 2015 I thought about the experiences of a number of beekeepers with Elgon bees, beekeepers that hadn’t been treating against Varroa for 10 or more years, with small problems from the mite. They had in common that they were isolated from other bees or/and dominated their area heavily with their bees.
Poul Erik Karlsen on the island Bornholm in the Baltic. He used 5.1 mm cell size. He is now retired and just have a few colonies left, after many years being a relatively big beekeeper on the island.
Sven-Olof Ohlsson in western Finland with around 200 colonies. He uses mainly 5.1 mm cell size, but also some 4.9. He is now retiring and going down in number of colonies.
Thore Harnkloo in the "deep" forest some 100 to the south of me. He is now retired and has sold his bees.
Hans-Otto Johnsen in western Norway with several hundred of colonies. He hasn’t been treating for 15 years. He uses 4.9 cell size. He also makes his own wax foundation with a commercially quality set up. He is now getting funding from the government to find out the important parts in his operation to help other beekeepers. Officials have found the varroa level is very low in his bees, and in the bees of his beekeeper friend Terje Reinhertsen who has been cooperating with.
Leif Hjalmarsson in the southern part of Sweden. He used 5.4 mm cell size. Another difference with him and the others was that his Elgon bees didn’t have any problems with the mite from the start. The mite had arrived in his operation some 5 years before he received 5 queens from me. He had all the time treated all his bees with Apistan, an effective miticide.
Leif started his Elgon colonies with very low levels of mites. After introduction of the queens in their colonies he moved them to an isolated spot in the woods more than 3 km from other bees. He didn’t treat his Elgons for more than 15 years. He got some new queens from me when he needed. But many colonies just shifted their queens themselves. Unfortunately he grew old as we all do and got a stroke. He passed away early in 2016. He was a good friend and a good beekeeper.
With isolation of about 3 km you avoid reinvasion of mites through so called silent robbing (you don’t recognize the bees are being robbed). And you also avoid bees seeking new homes, which are coming from crashing colonies. Silent robbing I propose will take place when mite populations will be bigger than 3-5 % varroa level, thus lowering the defense against silent robbers. The time for this is in times of nectar drought, mostly when varroa population is growing and brooding is going down later in the season.