When it comes to a colony that you're expecting to winter over, the right size matters, but what do we mean by the right size, and how is it determined? Typically, it's "seams" of bees used to determine size. So, looking down into the brood nest, the seams are the bees you can see between the top bars. Count the full seams, and that's it. The photo above would be considered a full 10 seams of bees.
Now that you have the count, it's easy because having less than five full seams in October puts you in the marginal zone for survival. That's why the time-honored tradition of taking your losses in fall finds its way into discussions this time of year because the chance of winter survival increases when you combine a small colony with a larger one. The cluster has an easier time with thermoregulation, and the colony can afford to lose more bees during the winter and still have a good chance to make it to spring.
This photo is what seven frames of bees will look like as they cluster in winter. In this case, the colony started with many more bees but as the winter progressed the colony shrank. Even so, this would be a good cluster for later in winter. So this October, do your mite counts and while you're at it, count the seams of bees. If you need help, send us an email, and we will help you determine what action to take.
Also, join the group discussion at Bee Talks every second Thursday of the month because there is much more to wintering than counting seams of bees. Check our upcoming events for more information.