http://www.extension.org/pages/62802/honey-bee-genetic-diversity-and-breeding:-towards-the-reintroduction-of-european-germplasm

Honey Bee Genetic Diversity and Breeding: Towards the Reintroduction of European Germplasm

Overall, it has been estimated that less than 500 queen mothers are used to produce around 900,000 daughter queens annually for commercial sale in the US. (Delaney et al. 2009).