Honeybee. Waggle Dance. Drones and Queens

For millennia honey from bees was the primary source of sweetness for humans. For this reason, as well as for its preservative and medicinal benefits, it has been highly prized. The wax that bees use to construct their honeycomb cells was also an important product, used in candles, polish, ointments, cosmetics, and inks. And from fermented honey a pale yellow wine—called "mead" in Europe, tej in Ethiopia—is made. It is thought to be one of the earliest alcoholic beverages ever produced.

Although all bees collect nectar and other plant secretions to feed to their young, honey in the normal sense is made by only four species in the genus Apis. Apis cerana (eastern honeybee) occurs in India, southeastern Asia, and China; Apis dorsata (giant or rock honeybee) occurs in the Himalayas; and Apisflorea (little honeybee) occurs in India and southeastern Asia. The most important species, however, is Apis mellifera, a native of eastern Europe, Asia Minor, and Africa that has been domesticated and carried by humans all over the globe.

The social behavior of honeybees is complex and has fascinated people for as long as honey has been known. A colony revolves around the activity of a single fertile female, the queen, whose sole occupation is laying eggs. The majority of the bees, up to fifty thousand in a large colony, are nonreproductive females called "workers."

The workers forage, collecting nectar (and pollen) from flowers. Unlike many other natural insect pollinators, honeybees practice "flower fidelity," tending to target the flowers of a particular plant species during each foraging trip from the hive.

This fidelity makes them one of the most important pollinators and has led to the large-scale use of mobile hive transporters—truckloads of hives are strategically positioned during key flowering periods in agricultural land. Honeybees are particularly important pollinators of alfalfa, berry crops, and fruit trees.

In the bee's honey stomach the nectar is transformed by reduction of water content and by enzyme inversion of the sucrose into glucose and fructose. It is then regurgitated into beeswax storage cells, capped with wax and kept to feed to the bee maggot brood, which is usually housed in another part of the honeycomb.

Waggle Dance. Targeting of certain flowers is made possible by communication between bees. Successful scouts return to the combs and perform the "waggle dance" to their sisters. This abdomen-shaking ritual takes the form of a figure 8 performed on the comb and closely monitored by other workers being recruited.

Direction to the food source (relative to the sun's position) is indicated by the orientation of the central portion of the dance on the comb, and the distance (energy required to get to the flowers) is indicated by the length of the central portion and the "tempo" of the bee's movements. Other "dances" are used to communicate daily and seasonal foraging needs and to choose new nest sites.

Workers also defend the colony using their barbed stingers to inject powerful venom. The stinger is a modified part of the egg-laying tube, hence only females (workers and queen) can sting. They also control the internal climate of the nest by bringing water, collected from puddles and ponds, onto the combs and by fanning air through with their wings.

The complex social structure of honeybee colonies derives, for the most part, from the unusual genetic system of sex determination. Most organisms have paired chromosomes in their cell nuclei, one virtually identical set from each parent. The sex chromosomes, however, are not identical (called "X" and "Y" in humans, for example, for their shape under the microscope), and they determine female (XX) or male (XY) gender. In honeybees an arrangement called "haplodiploidy" exists.

This arrangement occurs through all of the insect order Hymenoptera, which includes bees, wasps, and ants. Individuals with only one set of chromosomes (the haploid condition) are males, those with paired chromosomes (diploid) are females. When a queen mates with a male (a drone), she stores the sperm in the spermatheca, a sac inside her abdomen. As each egg is laid, it can be fertilized, or not, using the sperm store. Fertilized eggs (diploid, with two sets of chromosomes), become females, unfertilized eggs (haploid with only one set) become males.

Defense of the colony against an attacker leads to the death of many workers, who effectively commit suicide when their barbed stingers are torn from their bodies. The stingers, with muscle-contracting venom sacs still attached, remain in the enemy's flesh, thus increasing the intensity of the pain, but the bees perish.

Mathematical models can explain such "altruistic" behavior because even though a worker dies, her increased level of relatedness to all other workers in the colony means that her "fitness" in the evolutionary sense of passing on genes to the next generation is increased.

Drones and Queens. Drones are produced in small numbers throughout the life of the colony and develop from unfertilized eggs. They mate with queens, but because their genitalia are ripped out during mating they do not live long.

Development of queens in the colony is under complex control of pheromones (chemical signals) and seasonal factors. Specially constructed cells containing a fertilized egg are selected, and the grub is fed a special diet of extra honey and "royal jelly," a substance rich in sugars, vitamins, and protein secretions.

The extra nutritional intake allows a larger bee, with fully functional ovaries, to develop. Emergence of new queens causes the colony to divide. Some queens are killed, but eventually a new queen will take over the colony, while the old queen leaves with a cohort of workers to swarm and form a new colony elsewhere. This natural division of the colony by swarming was long the basis for beekeeping.

The origins of apiculture (beekeeping) are shrouded in prehistory. Bees appear to have been domesticated for many centuries before Roman times, after which there is good written evidence of beekeeping practices. Honey was probably first harvested, from wild colonies, during the Stone Age.

Bushman cave paintings made in the last two thousand years in the Natal Drakensberg Park of South Africa show aspects of honey gathering—stick figures of men climbing ladders to a colony surrounded by a cloud of flying bees. In parts of Africa and Asia honey is still collected in this way from wild combs in trees and on rockfaces.

Honeybees were already domesticated by the time of the ancient civilizations of Egypt, Greece, and Rome, and the basic techniques of honey harvesting remained relatively simple until the nineteenth century. Colonies were housed in crude containers, usually cylinders of woven grass or domes of straw called "skeps."

At the end of the foraging season the colony was destroyed and the honeycombs extracted. New colonies were either collected from wild swarms or from part of the domesticated stock during the natural process of division when part of the colony leaves to found a new colony.

Modern Beekeeping and Honey Production. The development of modern hives started with U.S. pastor L. L. Langstroth, who first made a moveable frame hive in 1851. Stacking layers of regular hanging combs means that brood combs (those where eggs are laid and grubs housed) can now be kept separate from storage combs (those used solely for honey storage); a mesh of certain size excludes the large queen, preventing her laying eggs in the storage cells, but allows free passage of smaller workers to bring in honey. At the time of honey harvesting all the bees can be excluded from the (usually) upper combs as the wax caps are removed and the honey drained off.

With the mass cultivation of sugarcane, people found another source of sweetness, but honey remains a major industry throughout the world. It also remains an endeavor that crosses cultural and class divides, being practiced by industrial-scale agricultural companies, smallholding farmers, and hobbyists alike.