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 February. 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 fall. 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