5.9. Drone brood production
This measure is best taken in spring or early summer when drones are being actively reared. It is nothing more than an extension of the Objective mode (4.1.) or Subjective mode (5.1.) limiting observations to drone cells filled with larvae or capped with pupae. Values for drone cells per cm2 for European bees range from 2.3 (J A Berry, University of Georgia, USA, pers. obs.) and 2.6 (Dadant, 1963); a good estimate for African races is 3.0 (Buco et al., 1987; Hepburn, 1983).