On this cold day with snow flurries I spent a little time thinking about the greatly improved hive survival experienced by beekeepers Fred, Gerard and Jon this winter. Was it our concentration on mite control last summer and fall or some other factor such as more benign weather? We had been preaching the necessity and benefits of good mite control all last year. Do we have enough evidence to draw a conclusion that it was the mite control and not the weather? So, I took a little time to review my notes from this winter and last winter.
This winter was milder than last winter through the end of December. Last year the below zero nights began in December, while this year they held off to January. By my count, last winter there were 15 below zero nights. This winter there have been 11 below zero nights so far. That could make one think last winter was worse than this winter.
But last winter the coldest night was -14F, while this winter we hit -30F. From this standpoint this winter was the worse of the two. Just looking at the below zero nights last winter had a total of 106 degrees below zero over the 15 days or a -7F average. This year a total of 121 degrees below zero over 11 days or -11F average. Again, this winter was again worse.
Last winter had seven below zero nights in a row. This year had only five below zero nights in a row. Repeated cold nights and days inhibit the cluster from moving to food and can result in starvation. Last winter was worse from this perspective.
Last winter the cold nights started earlier (December) in the winter, when the bee clusters should have been larger and better able to handle the cold. From this perspective this winter was worse because by January natural attrition within each hive would result in smaller clusters less able to withstand cold.
From my viewpoint the two winters were about the same with a slight edge to this winter being worse. Also our survival rates are significantly higher this winter.
Therefore, I feel the better mite control each of us practiced is the major factor in our better survival to date. It is also interesting that hives with either local or package queens are having the same excellent survival.
February is the time for the hives to start brood rearing. This makes a big demand on food resources within the hive. More food is needed because there is now brood to feed and also because the bees increase the brood nest temperature to 92F to ensure survival of the brood. Late winter starvation may occur if the hive runs short of food for these two functions. Now good beekeepers need to follow through and make a late February and mid-March feedings. Both sugar and pollen or a pollen substitute are recommended. Don’t be lazy and lose your hive at this late point. Get out there and either verify there is plenty of honey or by adding emergency feed.
We can discuss this at our February 16th club meeting: 9:30AM at the Caestecker Public Library in Green Lake. See you there.