If I Don't Control Varroa Mites Will My Bees Become Naturally Resistant to Varroa?

Unfortunately, no…

Not controlling Varroa will allow them to spread—not only to your other hives but often to all the hives within a few miles of your own bees. Not controlling Varroa in some manner is irresponsible as a beekeeper and inhumane to the bees. It’s just like how we would never neglect treating a pet for an infestation of fleas, mites, or ticks—especially if it could lead to their death. We should practice proper animal husbandry and take care of our bees just as well. Breeding bees to become consistently resistant to mites has been the lifetime pursuit of many brilliant beekeepers and scientists, but we aren’t there yet.

Three common outcomes when you don’t treat or intervene for Varroa:

1. Your hive does fine. This happens when they didn’t have a very high mite population to begin with, or you hit the beekeeping lottery and your hives are resistant enough to survive without treatment. This is very rare, but it can happen. Important to note: if you don’t test to confirm this, the odds are certainly not in your favor. If I had to guess, I’d say this is the case in less than 1% of hives in the U.S. There are always some beekeepers who say they’ve never treated for mites and their hives do fine—however, that is certainly not the norm. Another noteworthy point: even if your hive, in the very rare instance, survives with higher mite loads, you are still spreading mites to all hives within a few miles of your own. This is often called a mite bomb.

2. Your hive dies quickly. This is a common outcome. Mites weaken a hive by sucking the fat bodies from the bees and transferring viruses to both adult and developing bees. They can kill a hive quickly or slowly, depending on the mite population and the hive’s starting health. If mite numbers increase rapidly, a hive can go from a single deep box (or two deeps) full of bees to just a few frames of bees—or completely dead—in a matter of weeks.

3. Your hive becomes greatly weakened and dies slowly. This is the most common outcome. As mite populations steadily grow, the bees’ immune systems steadily decline. They contract viruses and other diseases and eventually die. Many beekeepers believe the hive was fine over the summer, but as the bees begin to cluster in cooler weather and the population continues to drop, the weakness becomes more apparent. Ultimately, after a few cold fronts, the colony dies.

What about VSH?

VSH, or Varroa Sensitive Hygiene bees, are bred to remove capped pupae infested with Varroa mites. They are also better at grooming themselves and removing mites. While it may sound like you can buy these bees and avoid treatments, that is unfortunately not the case. The vast majority of the time, you will still need to use some form of treatment. The best widely available VSH bees are perhaps 10–20% better at removing mites from themselves and the brood.

While that is an advantage, it isn’t nearly enough to control Varroa mites and expect a hive to survive.

It’s recommended to try a variety of bee breeds and see what works best for your area and hives. That may or may not end up being VSH bees. There are many other important factors—such as gentleness, honey production, and resistance to foulbroods—to consider as well. VSH should be viewed as a great place to start in combating Varroa mites, and as one of many tools used together to help keep them under control.

Blake Shook

Here's a short video where I discuss the topic of not treating bees to build resistance to Varroa mites

- Here's Lauren Ward's take on the subject -