If I Don't Control Varroa Mites Will My Bees Become Naturally Resistant to Varroa?
By: Blake Shook
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 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.
3 common outcomes to be expected when you don’t treat/intervene, in any way, for Varroa.
- Your hive does fine since 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 mites 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 that this will be the outcome. If I had to guess, I would say this would be the case with less than 1% of hives in the US. 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 thing to mention, is that even if your hive, in the very rare instance, survives with higher mite loads, you are spreading mites to all hives in a few miles’ radius of your own beehive. This has become known as a “mite bomb”.
- Your hive dies quickly. This is a common outcome. Mites weaken a hive both through sucking the fat bodies from the bee and transferring viruses to adult and developing bees. They can quickly, or slowly kill a hive depending on the mite population, and how healthy your hive was to begin with. If the population of mites increases rapidly, a hive can go from a single deep box or two deeps full of bees, to a few frames of bees, or dead, in a matter of weeks.
- Your hive becomes greatly weakened, and slowly dies over a period of months. This is the most common outcome. As the mite population steadily grows, the bee’s immune system steadily declines. They contract viruses and other diseases, and eventually die. Many beekeepers believe the hive population was fine over the summer, but as the bees begin to cluster as the weather cools, along with continued population losses, it becomes more apparent how weakened they are. Ultimately, after a few cold fronts, the colony dies.
What about VSH?
VSH, or Varroa Sensitive Hygiene bees are specifically bred to remove capped pupa infested with Varroa mites from the hive. They are also better at grooming themselves and removing mites. While it may sound like you can buy these bees and not treat for mites, 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 does have advantages, it isn’t nearly enough to control Varroa mites and expect a hive to survive.
It’s recommended to try a variety of breeds of bees and see what works best for your area and hives. That may or may not end up being VSH bees. There are many other very important facts, like gentleness, honey production, resistance to foulbroods, etc. to consider as well. VSH should be considered a great place to start in combating Varroa mites and one of many tools used in unison to help keep Varroa mites under control.
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 -