Re: Can varying levels of resistance been seen when using brood breaks to manage varr
Mite counts? A good rough guide but that's all. They can be deceptive there are so many variables this is why it's all so hard.
Factors we don't always consider that can affect mite count include is the hive in a position where it collects drifters? if so it will have a higher mite count. Did the hive start the season for some reason maybe beekeeper induced, with a higher mite count? As mite populations increase exponentially it could now have a much higher mite count. What's happening in the broodnest? The state of the broodnest could mean there is a lot of phoretic mites available for counting, or could mean there are very few phoretic mites available for counting.
Me, I don't count mites. Even if it could be done accurately, it still discounts the other factor, which is viral and other infections and ignores we should also be looking for bees with better than average tolerance to that. Because of this and to take all things into consideration, I use the trusty old "eyeball" method. Ie, I look at the brood. If all is perfect, I'm fine. If there is PMS (parasitic mite syndrome) visible, then that demonstrates that the combined effect of mites (whatever their number) and the viruses they are transmitting, is beginning to overwhelm the hive. Light PMS I may allow to continue to see how the hive deals with it. Heavy PMS, battle is over I'll act in some way to save the hive.
Although I currently treat any hive that needs it (heavy PMS), by using the tools described above and breeding from the best I believe my bees are going longer between treatments than they were a few years ago. So this method is making gains, where the cold turkey bond method killed every hive I did it to so no gains were made.
44 years, been commercial, outfits up to 4000 hives, now 120 hives and 200 nucs as a hobby, selling bees. T (mostly).