The Question I Was Trying to Answer
For the last several years, I have been asking a very specific question in my beekeeping.
What level of mite infestation is high enough to reveal something useful about resistance, but not so high that it simply destroys the colony before you learn anything from it?
That is the question that led me to a 5% threshold.
Not because I think 5% is a universal rule. Not because I think everyone should copy it. And not because I believe it is some kind of gold standard. I use it because I needed a practical line in the sand that would allow me to keep pressure on the bees, observe what they actually do under that pressure, and still intervene when a colony crosses into territory I consider too risky.
A Threshold Can Be More Than a Treatment Trigger
Most recommendations treat thresholds as simple intervention points. If the count hits a certain level, treat. If it does not, do nothing.
I do not look at thresholds that way.
In my program, a threshold is not just about deciding whether to treat. It is also part of how I evaluate stock. Colonies under that threshold stay in the game. Colonies over it may get some form of rescue, welfare intervention, requeening, or treatment, depending on the circumstances. The point is not to save every colony at all costs. The point is to learn which colonies can hold their ground under real conditions and which ones cannot.
That distinction matters.
If your threshold is so low that nearly every colony triggers intervention, then you may not be evaluating much of anything. You may just be treating by policy and calling it monitoring.
What the Yard Showed Me
In one of my yards, none of the colonies ended the season above 5%. They were all below that mark. Some were at zero. Some at one or two mites. Some at three percent. No chemical treatments had been used. The only meaningful disruptions to mite reproduction had been spring splits and nuc removal, both of which are part of normal management.
And yet, by late winter, the yard still stood at six out of eight alive.
That is where the question gets more interesting.
If colonies with one, two, or three percent infestation can still die over winter, then clearly the answer is not as simple as “low mites equals automatic success.” But at the same time, the colonies that survive under those conditions still tell you something important. They tell you which colonies can keep mite pressure relatively low without chemical support and still come through winter. That information carries weight.
The Balance Between Pressure and Loss
That is really what this threshold is about.
I am trying to keep enough pressure in the system to expose which colonies have something worth preserving, without creating a setup where losses become so severe that the whole exercise turns economically foolish or biologically meaningless. This is not about chasing a fantasy of perfect coexistence between bees and mites. That ideal has been much harder to pin down in a repeatable way than many people want to admit.
What I have found so far is more modest and more useful.
A 5% threshold is high enough to help reveal differences between colonies. It creates enough room to observe tolerance, resistance, and survival mechanisms without immediately flattening everything into the same treatment response. At the same time, it is also high enough that some colonies will still die beneath it. That is part of the reality. The threshold is not magic. It is a working line for evaluation.
Why I Do Not Use 1%
Conventional advice often says 1% is already too high and should trigger action.
For me, that is too low.
If one percent is always the line, then in practical terms you may as well not be monitoring for selection at all. You are simply monitoring to justify treatment. That may work for some operations, and if that is the goal, fine. But it does not help me answer the question I am trying to answer, which is how bees and mites coexist long enough for me to identify something useful about resistance and winter survival.
That is why I have stayed with 5%, even knowing it is imperfect.
What I Think the Data Is Actually Telling Me
So far, the data suggests something important.
A 5% threshold may still be high enough to allow losses, but it is also useful enough to help identify colonies with survival value and resistance potential when paired with other testing. It narrows the window of loss while still leaving enough variation in the system to learn from. That matters to me more than pretending there is a single clean formula that will make every result predictable.
I am not claiming to have solved the problem.
I am trying to know enough to make better decisions, keep more of the right colonies, and continue selecting in a direction that improves stock over time.
For now, that is what the 5% threshold gives me.
