The following will predict the probabilities of colonies reaching target size in February: Probability of colony reaching target size:
Predictions for February Bees
Frames of bees in September: [?]
Mites per 100 bees in September: [?]
Frequently Asked Questions
Can I use colony size and mite numbers taken in October if I put colonies into cold storage?
When we measured colony sizes and mite populations in October and tested for a relationship between
those values and colony size in February, we found that there were no significant correlation. This might
be because the overwintering population is being created in September. If the colony population is
infested with mites during development in September, the effects on the adults will be in place in
October and throughout the winter.
Will this tool work for colonies overwintered in outside apiaries?
We conducted an analysis similar to that used to generate predictions for colonies overwintered in cold
storage using colonies overwintered in apiaries. The analysis indicated that colony size and mite
numbers in September were not significantly related to colony size in February. A second analysis was
conducted that included frames of bees and mite populations in October, but again there was not a
significant relationship between colony size and mite numbers in the fall and colony size the following
Our findings may be because when colonies are put in cold storage, the colony size in February
is determined by the population size and longevity of workers in the colonies when they were put in the
facility. When colonies are overwintered in apiaries especially in areas with warmer winters, colonies
will rear brood and small colonies can be fed to stimulate brood rearing. The added variability due to
management practices and colony responses make it difficult to derive relationships between
September colony conditions and February colony sizes when colonies are overwintered outdoors.
Will this tool work if my colonies are in southern latitudes before going into cold storage?
That is a great question. We have one year of data, but it shows that colonies that are in southern
latitudes where brood can be reared throughout the winter behave very differently in cold storage than
those that were in northern latitudes in the fall. I do not think the program will accurately predict
chances of reaching target colony sizes in February if the colonies were in southern apiaries the previous
If you have questions, please email: GLORIA.HOFFMAN@USDA.GOV. We will answer them, and post the
information for others.
Refer to the ? mark under Predictions Tab on how to use the Cold Storage Overwintering Tool
The following will predict the probabilities of colonies reaching target size in February:Target colony size [Frames of bees]: [?]
Probability of colony reaching target size: