Who knows...but I have closely related colonies which are perfectly OK
It shows that if you are monitoring you should monitor all of them, not just a sample
It's a conundrum isn't it ?
Varroa in it's native habitat of Asia lives in a non-destructive relationship with it's host - Apis Cerana - there it is found almost entirely in drone cells and with restricted virility as a result of temperature and humidity. These bees show highly hygienic traits and grooming behaviours that have been established over millenia and the host and parasite, generally, live in a balanced state. There is some evidence that where varroa has spread to the Cape bees and the africanised bees in the USA (and even AM in Cuba) these bees have developed some resistance to varroa in a condensed time frame.
https://link.springer.com/article/10.1007/s13592-022-00977-8
Bees are clever and adaptable creatures - they learn behaviour quickly and appear to inherit desirable traits (it's why we all seek to improve the stock we keep by selective breeding and rear from queens that show desirable characteristics in their offspring). Varroa has been in the UK since the 1990's there is every reason to believe that at least some of our bees are developing coping mechanisms.
I'm not suggesting that we should all stop treating - but, if colonies ARE (with proper testing) showing low varroa levels on an ongoing basis then there is a good case for allowing these colonies to exist without treatment - perhaps, just perhaps, these are the future of beekeeping in the UK. 30 years of treatment does not seem to have led to a solution.
I've said it since my earliest days of beekeeping - what we should have is national varroa month (September) where EVERY beekeeper in the UK is legally obliged to treat their bees for varroa - properly - I'm sufficiently liberal to say that it can be their treatment of choice - my preferred treatment would be OA by sublimation. Reducing the mite load on a national basis - at the same time - would have a major impact on our bees - a second varroa month (March ?) where mandatory follow up treatment is required would consolidate the reduced mite load nationally.
The considered and accepted wisdom is that the vast majority of honey bees in the UK are in managed colonies - yes, there will still be feral colonies out there with levels of varroa but, if we tackle the managed colonies nationally, this will benefit the feral colonies. If the perceived wisdom, that feral colonies are varroa bombs, they will die out - along with their varroa load - or their mites will migrate to managed colonies and will be eradicated in the 'national varroa months'. Or .. the feral colonies will survive and become an asset to our national bee stock.
I'm under no illusion that this is ever going to happen ... getting two beekeepers to agree on anything is hard enough - inflicting a national, mandatory, requirement on the beekeeping community has little chance of success.
In the meantime, those of us who are TF may be in the vanguard of the future ... ?
