Biology Reference
In-Depth Information
2.5.8 Tasks Are Linked, Not Independent
Worker honey bees change tasks as they age. h ese changes do not oc-
cur in i xed, temporally linear sequences but instead rel ect changes in
physiology of the bees and their location in the nest. h ere is a relation-
ship between the performance of tasks and the location of bees in the
nest. Bees emerge from their cells as adults near the middle of the nest,
where the queen lays eggs in the individual cells of the combs, the eggs
hatch, and younger nurse bees care for and feed the developing larvae.
Tom Seeley grouped many of the tasks into four categories, or behav-
ioral subcastes, that correlate with location in the nest. In his study, the
youngest bees (0 to 2 days old) stayed near the center of the nest where
they emerged and engaged primarily in cell-cleaning behavior. At er
two days, they moved to engage primarily in brood care, still in the
central part of the nest; however, at er about 11 days, they moved out of
the brood nest and engaged in receiving, storing, and processing food.
At the end of their third week of life they began foraging outside the
nest. Second-order receiver bees (those that receive food from primary
receiver bees) engaged in both food-storage and nurse bee activities.
2.5.9 Foraging for Work, or Temporal Development?
h e centrifugal movement out of the center of the nest to the peripheral
regions and the associated changes in stimuli encountered and tasks
performed appear to be programmed developmental changes. h ey are
not strictly age related because they can be retarded or accelerated with
changes in the colony environment. An alternative hypothesis is that
young bees get crowded out of the center of the nest by newly emerging
workers and move to other areas of the nest and look for work. Forag-
ing is a dangerous occupation and is performed by the oldest bees, so
mortality is high among foragers and opens up vacancies in that task
group. As a consequence, there is a constant l ow of bees from the
brood nest to the periphery and to the i eld.
h e “foraging-for-work” hypothesis of Nigel Franks was tested by
Nick Calderone. He placed brood combs in an incubator where the
