A speaker at our club said that OAV appears to have a physical reaction from the bees or mites. OAV either cuts the mites or stimulates the bees to start grooming. As such, mites can't develop resistance. It is like developing a resistance to a knife wound.
I did some literature search and you are right, I could not find a good scientific paper demonstrating varroa’s resistance to apivar. I also could not find a paper showing resistance (of dog ticks) to tick collars (Amitraz is delivered in a similar manner as in apivar). In contrast, there are multiple papers regarding resistance of cattle ticks. To cattle, amitraz solution is applied as a dip or low pressure hand spray, which makes it harder to control dosage, I suppose.
No, but thermal treatments could select for mites that can withstand higher temps. Thermal treaters may want to diversify as well.
The article you cite makes no mention of the potential of thermal treatments to select heat-tolerant mites.
As psm mentioned, the article you linked to says nothing about the evolution of resistance. From a strictly evolutionary perspective, thermotolerance (tolerance to heat) is relatively easy to evolve. There has been a lot of work done on this is Drosophila (fruit flies), and improved thermal tolerance can appear in just a few generations. The evolutionary mechanism of this is well understood - essentially, the flies make a little more of a family of proteins called "heat shock proteins"; simply by increasing the amount of these proteins in their cells, insects can become tolerant of higher temps in just a handful of generations. Thermal treatment for varroa is relatively new, but even so, its already been shown that they respond to heat stress in the same way of insects where the evolution of thermotolerance has already been observed.
Thanks for the very interesting link. Very good point and information to have. Learned something new. The biggest and most important reason I come here. :thumbsup: So far, I have done about 350 thermal varroa mite treatments with the Mighty Mite Killer. I will definitely be mindful and on the look out for evidence of resistance. If this in fact does turn out to be the case, perhaps rotating thermal treatment with other chemical treatments may be a better course of action. So far, I have had excellent results treating mite with thermal treatment but this does not mean that it is the "magic bullet" against varroa mites. Ultimately I believe the best and most lasting means of ridding the varroa mite as a harmful parasite of honey bees is what Randy Oliver is pursuing in trying to develop and genetically evolved honey bee that has developed successful resitance traits. In the meantime, I prefer to use successful and effective non-chemical treatments if I can. The cost savings I have realized in not spending money on chemical treatments has paid for all of the equipment I purchased for thermal treatment in about 2 rounds of treatment. Just one treatment of my apiary with Apivar costs me about $1,500 for example. MAQS is not exactly inexpensive either. Again, thanks for the link. It was an interesting and informative read.
On another similarly related note, research into thermal treatment is beginning to show some unexpected benefits and results with respect to lowering viral loads in honey bees. View attachment temperature bee virus (003).pdf
