Reading the Mite Drop: Our July Varroa Check in Svinninge
On a warm July afternoon we finally sat down with the sticky board, a scoop of bees and a jar of powdered sugar. Here is what the count told us — and the worry that came with it.
The check we keep putting off
There is a job in July that we are always a little slow to face. The honey is coming in, the meadows around Svinninge are at their fullest, and everything looks well. Sliding the sticky board under a strong, humming colony to count its varroa feels almost rude — like asking a healthy friend for a blood test at a summer party. But that reluctance is exactly the trap. Varroa is the quiet killer behind most of our Nordic winter losses, and by the time you can see the damage, it is far too late to undo it.
So on a still afternoon this week, we made ourselves do it. We sat down properly, with the board, a scoop, and a jar of powdered sugar, and we counted.
Two ways of asking the same question
We use two methods, because neither is perfect on its own.
- The sticky board (natural drop). The Swedish first-line check. A mesh floor and a greased board under the brood nest, left for a few days, then we count the mites that have simply fallen. Easy, non-invasive, and it ties straight into numbers we trust for our climate.
- The sugar roll. About 300 bees — roughly half a cup — scooped from a brood frame, carefully making sure the queen isn't among them. A tablespoon of powdered sugar, a gentle roll, and the mites tumble off onto white paper. Non-lethal, and the bees stagger back into the hive dusted and indignant but unharmed.
We lean on the drop for the trend and the sugar roll to sanity-check it. One lesson we've learned the hard way: with this much brood in July, adult-bee tests underestimate. Most of the mites are hidden under the cappings, breeding. No detection is never the same as no mites.
What the numbers meant
Here is the part that makes your stomach tighten while you wait for the board.
For our conditions, the figure we watch is the natural drop per day. The rule of thumb we trust from the Stockholm-region beekeepers is sobering in its simplicity: about 1 mite falling per day in late June already means somewhere around 120–130 mites in the colony. Up to roughly 3 a day and a colony is still winterable if you act. Over 3 a day, you treat now — akutbehandla, no waiting for a convenient weekend.
Our strongest hive came in at a little over one a day. Not a disaster. But not the "nothing to worry about" we'd quietly hoped for, either — because the arithmetic of varroa is merciless. The population roughly doubles every three weeks through the brood season. There are said to be a hundred times more mites in August than in March. One a day now is not one a day in six weeks; it is the seed of a real problem sitting under the honey.
The responsibility of it
What stays with us, every year, is the weight of the thing. These mites don't mostly kill by numbers — they kill by feeding on the fat body, the very tissue a bee needs to become a long-lived winter bee, and by spreading deformed wing virus into the brood that has to carry the colony to spring. Damage the winter bees in August and no amount of wrapping or feeding saves them in January.
And this is our region's uncomfortable truth: the Stockholm area loses more colonies over winter than the rest of Sweden — over twenty percent in some recent years — correlated with deformed wings people spotted the summer before. That statistic isn't abstract to us. It is our postcode. A July mite check is the single most locally-relevant thing we can do before the August treatment window.
So we've made the plan concrete, written in the medicines log as we're required to: formic acid after the final harvest, timed for the right temperature window — not too cold to work through the cappings, never above 25°C. Then oxalic acid in the broodless late autumn. The July number didn't tell us to panic. It told us when.
Where nutrition fits — and where it doesn't
We'll be honest about the other half of what we do, because it's easy to overstate. We keep our colonies strong and well-fed — this season with Dr. Gost — on the sound principle that a well-nourished bee builds better fat reserves and a more resilient immune system, and carries the winter better. A strong colony tolerates a knock better than a weak one.
But we say this plainly, to ourselves most of all: nutrition supports the winter bees; it does not touch the mites. No feed, no supplement, nothing we pour in the top will bring a drop count down. Good food helps the bees survive what the varroa work prevents. It is never, ever a substitute for the count and the treatment.
That's the quiet responsibility of keeping bees this far north. You sit with a scoop of your own bees and a sheet of paper, you count the small brown things, and the number tells you what you owe them come August.