Overall, the main threats to a honeybee colony clustering its way through winter are cold temperatures, lack of sufficient food stores, and colonies, especially small or weak ones, that are affected by diseases or high varroa mite loads.
When cold temperatures are combined with inadequate food stores, it can mean certain death for even a healthy honeybee colony. To reach their stored resources, the cluster must stay warm enough to move there together. Honeybee colonies ideally need to have roughly 60-80lb of honey stored before winter arrives to have enough to sustain them through spring.
- To mitigate this risk… beekeepers can open their hive briefly to add emergency feed, if needed, like candy boards or “winter patties” placed directly atop the cluster, but only if conditions are safe enough to do so.
Beekeepers should keep in mind that winter bees enter their tight-knit cluster when temps reach 40 degrees F or below and must remain there to survive, so any disturbance to their beehive can upset the cluster and put bees at risk. Excess moisture inside a beehive is a potentially big disturbance and danger to bees clustering inside and don’t forget that certain pests, like mice or other animals, can disturb bees trying to stay warm, too.
- To mitigate these risks… beekeepers should ensure beehives are well-insulated and ventilated and that entrances are reduced before the cold sets in, and take great care to disturb their hives as little as possible. (Learn even more about managing pests, big and small, in the “Read More” section below)
Colonies that head into winter with high levels of varroa mites and/or with the diseases they may cause could be especially at risk for not being healthy enough to survive. In the fall months, beekeepers should consider combining any honeybee colonies that are too small or weak to survive on their own. Weak colonies have less ability to maintain hygienic behaviors that help them keep varroa mite levels at bay.
- To mitigate these risks… beekeepers should make sure they have an integrated pest management plan in place at the start of each season to test for varroa mite levels and apply treatment as needed. If you are concerned that your bees may need a varroa mite treatment once the cold has arrived, an oxalic acid vaporization treatment is a safe option as it doesn’t require you to open the hive.
Read More
Overview of the Main Threats to Bees
Preparing Honeybee Colonies for Winter
Preparing for a Deep and Long Winter *
* Colony Member-Only Content
