Varoa mites are incredibly hard to control. Back in undergrad I worked in a fruit fly lab, and we would periodically have outbreaks, despite being about the most isolated, sterile population of insects you can imagine.
I doubt that there's any hope at all of controlling mites in free-roaming honeybees. I'd wager that we've done damage with overuse of miticides (which are insecticides, btw -- the article doesn't connect those dots) in a misguided attempt to control nature.
There's a company called, Greenlight Biosciences, that's developing an RNA-based pesticide for Varroa Mites. Last I spoke with the CEO, he mentioned positive results from trials.
That's cool, in a "better living through chemistry", 1950s man-in-a-white-labcoat sort of way. But when it comes to this stuff, I tend to be a bit like Ian Malcolm in Jurassic Park: they're so focused on whether they could, that they never considered if they should.
Probably the better solution here is to stop trying to do industrial farming of bees, and move to a system where local populations of pollinators are cultivated and maintained year round. But sure, RNAi is probably better than the chemicals they're using now.
Yes, mites are arachnids, but this point is pedantic. Miticides don't work by counting legs and body segments.
Consider Amitraz [1]. It is both an insecticide and a miticide, and the method of action is on the central nervous system. Fluvalinate [2], another common one, is also broadly toxic to many different organisms.
I would say that the pesticide immunity genes arise because of evolutionary selection, but once they come into existance commercial beekeeping practices quickly spread those genes from hive to hive and across the country.
You might be right that the physical distribution plays a role, but the partial selective pressure of insecticide is like a resistance-generating machine -- as anyone who has tried to kill cockroaches will tell you.
Regardless, I think we both agree that the extremely unnatural pressures of industrial agriculture are a root
cause here.
For example, Scandinavian countries that have made a concerted effort to only prescribe antibiotics to humans when they are medically necessary saw the genes for antibiotic resistance becoming less prevalent.
Unfortunately, America still allows agribusiness to feed livestock a constant stream of lower dose antibiotics, because doing so makes animals more efficient at turning feed into muscle.
I doubt that there's any hope at all of controlling mites in free-roaming honeybees. I'd wager that we've done damage with overuse of miticides (which are insecticides, btw -- the article doesn't connect those dots) in a misguided attempt to control nature.