Billy Davis and Sean Robertson demonstrate the Testing of bees for Hygienic Behavior using liquid Nitrogen. This testing should only be done when the evening temperatures are above 43 degrees Fahrenheit so the bees will not be in cluster and will be actively at work in the hive. Here in Northern Virginia, we do this in late March and early April when we have confidence that all of the bees in the hive are daughters of the current queen.
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