Two years ago I was asked to talk to a group in Essex and show them my Varroa records which covered my knock down rate. Many were surprised that with two doses of Apiguard followed by Thymol patties one could knock down, in some hives 2500 plus, and at the end of treatment have a zero weekly count.
Now all my supers are off in August and that's when I start treating and feeding. Some people claim they get a poor knock down with Thymol products but then told me they don't start treating until October or even November!! (even people in Herts) I thought by now, most people understood that Thymol products need a reasonable temperature to be effective, such as the average we get in August & September but it appears some still haven't learnt the lesson.
When I asked why they treated so late I was told that honey was still coming in. Frankly if these people think they are going to get full supers in September and October they must be on a different planet to me. Any honey which comes in at this time goes straight into winter stores.
There are others who say you must not feed too soon because you restrict the brood nest. Well I've always found bees stop taking down feed when THEY decide they have enough stores and if you've knocked down 2500 mites out of your brood nest Then those dead mites will not be damaging your young winter bees and therefore a smaller brood nest is viable.
I realise that some people are trying all sorts of concoctions, all unapproved and some of which are dangerous to us humans. There may come a day when a jar of English honey is tested and residues of a banned food substance will be found, the affect to our beloved hobby could be catastrophic. We will not be able to blame Varroa, just ourselves.