From Society to Genes with the Honey Bee
A combination of environmental, genetic, hormonal and neurobiological factors determine a bee's progression through a series of life stages
Basics of Bee Behavior
The so-called social insects, including honey bees, live in societies that rival our own in complexity and internal cohesion. For instance, honey bees always follow three rules: They live in colonies with overlapping generations, they care cooperatively for offspring other than their own and they maintain a reproductive division of labor. A colony arises from a queen that performs one task, laying lots of eggs, sometimes as many as 2,000 in one day. Her daughters, called workers, basically take care of the colony—doing everything from foraging for food to building the hive—but they generally do not reproduce. As one might expect, it takes many workers to run a hive, and some honey bee colonies consist of as many as 60,000 workers. Finally, a colony's males, called drones, can usually be found in the hive, where they do essentially nothing. The drones specialize in reproduction, which takes just a couple of hours on a sunny day when they fly to mating areas away from the hive. Once a drone mates, he dies.
A further division of labor exists among the workers. Although a worker's adult life span is just four to seven weeks, it undergoes a series of transitions. A worker usually spends its first few weeks tending to duties in the hive and its last few weeks foraging for food outside the hive. During the hive phase, a worker starts out with a couple of days of cell cleaning, literally removing debris from cells in the hive that are used to raise other bees or to store food. Next, a worker serves as a nurse, caring for and feeding larval bees. Toward the end of the hive phase, a worker spends its time processing and storing food and maintaining the nest, including building new sections of hive. Some workers also perform a few other tasks along the way, including guarding the hive or removing corpses. Finally, a worker switches to foraging, which is probably the most challenging task of all. To be a successful forager, a bee must learn how to navigate in the environment and obtain nectar and pollen from flowers. Foragers also communicate the location of new food sources by means of the famous "dance language." These transitions in occupation typically do not arise abruptly. For example, a worker might slowly decrease its nursing duties and become gradually more involved in maintaining the hive.
Behavioral development in honey bees is a powerful system for integrated analysis. Although it occurs naturally in the field, some underlying mechanisms can be analyzed in the laboratory. Moreover, honey bees have been closely associated with humans for millennia because of their special status as prolific producers of honey and wax and as premier pollinators for our food and fiber crops. As a result, we know more about honey bees than just about any other animal on earth. One consequence of this wealth of knowledge is that the natural social life of honey bees can be extensively manipulated with unparalleled precision.
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