Counting mites

It's mid July. Anne's mentor hands her a plastic jar, a measuring cup and a bottle of rubbing alcohol. Today, he says, we find out how many mites you have. Anne expected to peer at bees looking for mites. Instead she is about to do a little arithmetic.

You can't count mites by looking at the bees, because most of them are hidden in the brood. So beekeepers take a sample of bees and count the mites that come off them. In Ontario, most beekeepers who monitor use a wash or a roll.

The standard method is the alcohol wash. First, find the queen or make sure she isn't on the frames you sample. Then shake bees from at least three brood frames into a tray, and scoop half a cup. That's about three hundred bees.

Put them in the jar and cover them with seventy percent alcohol, about two centimetres above the bees. Put the lid on and shake hard for two full minutes. Then pour everything through a mesh with one eighth inch holes into a white pan, and count the reddish brown mites.

Now the arithmetic. Three hundred bees, so divide the number of mites by three. That gives you mites per hundred bees, which is the same as a percentage. Nine mites in your sample means three per hundred bees, or three percent.

The sugar roll works the same way, except you shake the bees in powdered sugar instead of alcohol, and the bees survive. It's gentler, but it's less reliable than a wash.

The third tool is the sticky board. You slide a sticky sheet under a screened bottom board, leave it for one to three days, then count the mites that have fallen onto it, and work out how many fell per day.

How often? Ontario's ministry sets a minimum of early spring, July and August. After the heavy losses of recent winters, it now strongly advises sampling every month through the season. Always sample before a treatment and again afterwards, to prove it worked. And in a small yard, test every colony, not just one.

You're in good company with the wash. In the latest national survey, eighty two percent of Ontario beekeepers who responded used a wash or a roll, and about a quarter used sticky boards.

Write every count down, with the date and the hive. The numbers only become useful when you can see them rising.

Now let's change one fact. Suppose Anne tests only her strongest hive and gets two mites. Good news, she thinks. But the hive next to it, the one that has been robbing a weak colony, might be at six percent. Each colony has its own mite story, and a small yard means every one gets tested.

The mistake beginners make is not counting at all. In twenty twenty five, one in five small scale Ontario beekeepers did no mite monitoring. A jar, a cup and two minutes of shaking are what separate guessing from knowing.

Here is the rule, in one breath. Wash about three hundred bees from the brood frames in alcohol, count the mites and divide by three to get your percentage, test every colony at least monthly in season, and always test before and after treating.

Next, what those numbers mean, and when you have to treat.