4.3. Special considerations for measuring adult bee populations in African bees

When it comes to African bees, the methods described in 4.2. must be modified to account for the fact that these bees immediately fly when disturbed.

1. Two observers plus a dedicated data recorder are recommended as before.

2. The key difference is that each observer makes a visual estimate of the percentage surface of the comb occupied by bees immediately as one of them withdraws it from the hive. Each observer is responsible for only one side of a comb.

3. To minimize loss of bees it is necessary to keep the hive intact as much as possible, working downward, removing the lid then first measuring bees in honey supers, then bees in the brood chambers.

4. Raw data are converted into colony bee population using Table 2 and the methods given in Fig. 6).

5. An alternative to visually estimating bees on combs is to rapidly remove each frame and immediately shake the bees into a large plastic bag. The bag is weighed to determine total net weight (kg) of bees, then a fresh sample of ca. 20 g bees collected. The bees in the bag are returned to the colony and the sample taken to the lab where it is weighed, frozen, and the bees counted to determine g per bee. Dividing total net weight by g per bee gives colony bee population.