2.5.6. Obtaining workers of known age

Obtaining workers of known age (counted from emergence) can be accomplished by having them emerge in an incubator, marking them and replacing them in their colony for the desired duration. Refer to the BEEBOOK paper on ‘maintaining adult honey bees in vitro under laboratory conditions’ by Williams et al. (2013) for more details on incubator conditions.

  1. Select a brood comb with capped cells.
  2. Inspect the comb for emerging workers.
    If none are observed, uncap a few cells to determine the age of the pupae (see section 2.5.4. ‘Recognising the age of pupae’). The presence of late stage pupae (dark eyes) indicates that workers will begin emerging within a few days.
  3. Place the selected frame in a frame cage (see Fig. 12 of the BEEBOOK paper on maintaining adult honey bees in vitro under laboratory conditions by Williams et al. (2013)).
  4. Place in the incubator at 35°C and 60-70% RH.
  5. Inspect daily (or when needed) and remove freshly emerged workers.
  6. Collect workers when a sufficient amount can be collected at once; discard or reintroduce the workers into colonies if their number is insufficient and wait until enough young workers have emerged.
  7. Mark an excess of workers with colour paints (see section 2.3. ‘Marking individual bees’ of the BEEBOOK paper on behavioural methods by Scheiner et al., 2013).
    Different colours or marking codes can be used to mark workers of the same colony on different days.
  8. Allow some time for the paint to dry.
  9. Reintroduce workers into their colonies.
    If workers are attacked by nest mates, spray them with sugar water or reintroduce them in a cage plugged with candy (for a recipe, see the BEEBOOK paper on ‘maintaining adult honey bees in vitro under laboratory conditions’ by Williams et al. (2013)) so that they can eat their way out. This will increase their acceptance.
  10. Inspect colonies and collect marked workers at the desired time.