2.5.1. Obtaining brood of known age
To obtain brood of known age, a queen can be caged on a frame on a particular day for a few hours. The duration of the caging is determined by the quantity and age range of the brood needed. For example, if more brood is required, the longer the queen is left in the cage. In this case, the age range of that brood increases. For example, the comb area in which the queen laid eggs during 4 hours will hold brood between 20 and 24 hours of age, 24 hours post caging the queen. Given that queens can lay 2,000 eggs per day during the fastest growing stage of the colony, approximately 100 eggs can be obtained every hour. During less beneficial periods, a lower number of eggs can be obtained. If larger amounts of brood of a narrower age range are needed, queens of several colonies need to be caged. This also allows reducing the disturbance of individual colonies in case the brood needs to be collected at frequent intervals. If large amounts of brood of known age are needed from a single colony, several replicates at different times need to be done.