Biology Reference
In-Depth Information
into a terminal state of being a laying-worker colony. Laying-worker
colonies of temperate populations of bees begin with a few bees engag-
ing in egg laying, usually beginning within 12 to 28 days at er losing
the queen. h e eggs are very quickly removed and consumed by bees
that inspect cells. Eggs laid by workers are in some way distinguishable
from eggs laid by queens and are eaten by nurse bees. Initially, no eggs
survive to hatch. h en over time, more bees begin laying eggs and fewer
bees engage in egg eating, the egg eaters are probably becoming egg lay-
ers, and some larvae are reared into mature drones. As time passes,
more bees lay eggs and fewer forage, and eventually chaos reigns where
the larvae die, the adults age and die, and the colony dies. However, a
colony may produce up to 6,000 drones before it succumbs, providing
opportunities for workers to have some reproductive success if any of
the males get lucky.
h ere is evidence in the form of caste-specii c reproductive behavior
that workers do produce successful sons. Honey bees construct three
dif erent types of cells for brood rearing: small worker-sized cells, some-
what larger drone-sized cells, and large queen cells. Queens control the
fertilization of eggs when they lay in worker- and drone-sized cells to
produce either females or males. Unmated virgin queens show a bias for
laying eggs in worker-sized cells; they do not “know” that they are not
inseminated. Unfertilized eggs laid in worker-sized cells produce smaller
drones, about half the normal size, with reduced numbers of spermato-
zoa, and probably are not competitive for mating with queens. Workers
are not mated, have no sperm to fertilize eggs, and show a signii cant
bias for laying eggs in drone-sized cells, which result in full-sized, fully
functional males. h erefore, the egg-laying behavior of unfertilized
workers, producing competitive sons, is probably a caste-specii c adap-
tation that could not have evolved without the reproductive success of
the drones produced by workers.
Gene Robinson and I showed that workers with dif erent fathers
within the same queenless colony dif er in their likelihoods of laying
eggs and engaging in oophagy (the consumption of eggs laid by work-
ers). h ere is genetic variation. Workers show dif erent physiological
and behavioral responses to the absence of the pheromonal inhibitors
