2.1.2. Where to sample?
To determine proper locations for sampling
inside a beehive, one must consider colony heterogeneity in time and space.
Feeding brood, and capping and trimming of cells takes place in the brood nest.
Other activities such as cleaning, feeding and grooming, honey-storing, and
shaping combs take place all over frames (Seeley, 1985). Free (1960) showed an equal
distribution of bees of successive age classes on combs containing eggs, young
larvae, and sealed brood, although there were proportionally more young bees
(4-5 days old) on brood combs and more old bees (> 24 days) on storage
combs. Older bees were overrepresented among returning bees at colony
entrances. This was supported by findings of van der Steen et al. (2012), who also
reported that age classes are distributed in approximately the same ratio over
frames containing brood (Fig. 1).
Fig. 1. The percentage distribution of age classes recorded between 24 August and 20 September for pooled colonies of Apis mellifera in the Netherlands. The different shades represent different age classes. The distribution of age classes did not differ among frames (p = 0.99). There was also no difference between the mean number of bees per frame (p = 0.94). Adapted from: van der Steen et al. (2012).