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Honey Bees
Biology and Behavior
Products of the Hive
Pollination
Enemies of the Honey
Bee
(Apis mellifera L.) preceded humans
on earth by 10 to 20 million years. Honey bees are one of the oldest forms of
animal life still in existence from the Neolithic Age. Primeval humans gathered
and ate the honey and honeycombs of wild bees, the only available sweet, as far
back as 7000 B.C. Bronze Age societies celebrated preindustrial triumphs by drinking
mead, probably the first intoxicating beverage, fermented from honey. In fact,
the words mead and mellifera (the specific name for honey bees), which are similar
in several languages, were derived from root words referring to honey bees, liquor,
doctored drink, etc. In the past, words for mead, honey, and honey bee have been
used interchangeably, revealing the importance placed on the alcoholic beverage
derived from honey. Like honey, beeswax has been prominent in ancient folklore
and mythology. In the pre-Christian era, wax was offered as a sacrifice to the
gods; used in the rites of birth, circumcision, marriage, purification, and death;
and used in embalming, sealing coffins, and mummification. The use of beeswax
in religious candles carried over into Christian times and led to beekeeping by
clergy and monks in order to ensure an adequate supply of the raw material. In
the past, beeswax served as a medium of exchange and taxation; it was exacted
as tribute from conquered nations and was used in writing, painting, sculpturing,
and protecting works of art, as well as for illumination. Honey, beeswax, and
propolis (a mixture primarily of plant resins and beeswax that bees use in nest
contruction) have been used extensively in pharmacopoeia since 2700 B.C. The principal
medicinal value of honey arises from its antibacterial properties when used as
a wound dressing. Honey bees originated in southern Asia, probably in the region
of Afghanistan. The earliest record of humans gathering honey from wild colonies
is from 7000 B.C. Man first kept bees about 3000 to 4000 B.C., perhaps as early
as 5000 B.C. There is no way of knowing to what extent honey bees have evolved
since then; we can assume that some evolution has taken place, particularly with
regard to the social organization of the colony and foraging behavior. Apis mellifem,
the most widely distributed of the species of Apis, is not native to the Americas.
The first record of the introduction of honey bees to the western hemisphere was
in 1530 in South America. It was introduced to North America by colonists from
Holland in 1638. Since bees visit a broad range of host plants and are able to
conserve heat by clustering, they have become widely dispersed and are now found
throughout the world. Honey bees are limited in their distribution mainly by an
absence of suitable forage and/or less than 19.8 cm (7.8 inches) of rainfall annually.
The scientific name, Apis mellifera, was given the honey bee by Carolus Linnaeus
in 1758. It liter- ally means "the honey-carrying bee * " A more descriptive name,
A. mellifica, or "the honey-mak- ing bee ' " was proposed in 1761. While this
second name more accurately describes honey bees (which carry nectar but make
honey), the rales governing precedence in scientific nomenclature dictate that
the earlier name be retained. Nevertheless, the term A. mellifica can still be
found in some bee literature. top?
Honey bees and their life history and products were topics of study for early
philosophers, such as Aristotle, Pliny, and Virgil. Many others have studied bees
throughout history. Yet, most basic knowledge of the natural history of the honey
bee has been gathered only since the sixteenth century. Twentieth-century scientists
have revealed the nature of honey bee sensory systems, behavior, communication,
and population dynamics. For example, it is now known that while honey bees do
not possess the fine-grained retinal mosaics of humans, they can navigate with
precision by optically scanning the sky's polarization patterns through their
ultraviolet receptors. Moreover, they easily perceive other colors and rapidly
flickering patterns (as in flight at close range). Honey bees possess senses of
taste and smell about as acute as those of humans and even more acute for some
flavors and aromas. Other revelations are fast emerging about the flight muscle
physiology of bees, their learning, memory, dances, chemical communication systems,
and reproductive physiology. Although it is often more appealing to believe that
bees are somehow special, honey bees are simply insects. Careful study of the
literature reveals that many insects behave and function in the manner of honey
bees; that is, they generate and conserve heat, raise young, forage, communicate,
swarm, store provisions (some even garden), and pollinate or otherwise provide
food for humans. Moreover, they do so just as efficiently as do honey bees. Honey
bees may seem unique because they express all the above behavioral and physiological
traits; but special combinations of traits such as these are present in other
insects, in plants, and in animals, where they are equally compelling. So we must
ultimately conclude that physiologically, behaviorally, and biochemically honey
bees are just insects, remembering, of course, that insects themselves are quite
remarkable. Although honey bees (and other bees) are often confused with their
near relatives, the wasps, bees can be easily identified by their fuzzy appearance
(branched body hairs), robust body, and flattened hind leg. There are more than
20 races of honey bees, the result of natural selection in their respective homelands.
But only 4 principal races are important to beekeeping in the northern hemisphere:
the Carniolans, Italians, Caucasians, and Dark bees. In the southern hemisphere,
other races are also important. Honey bee colonies are perennial and nearly worldwide
in distribution; they are distributed from the tropics to subarctic regions. This
is possible because they hoard resources and because they can thermoregulate their
nests, by fanning to evaporate water for cooling, by metabolizing honey to produce
heat (0.1 cal per minute per bee), and by clustering to conserve the heat they
produce. Other insects are capable of producing similar levels of heat energy;
for bees, however, temperature regulation via clustering is the key to winter
survival. Feral (wild) colonies nest in hollow trees, rock crevices, and ground
holes. They seem to prefer living trees. In the northern hemisphere most nest
entrances are knotholes facing southwest, undoubtedly because this is the side
of the tree that weathers and cracks first. Acceptable cavities are approximately
40 L (about the size of a one-story-deep Langstroth hive), and wild colonies therein
consist of about 18,000 to 20,000 bees in the most populous summer months. Unlike
most other insects, bees build their nests out of their own body products, primarily
wax and salivary secretions. Over the years apiculturists have gathered statistics
in order to better explain the organization and activities of a colony of kept
honey bees. While such figures are useful and interesting, one must keep in mind
that they depend on season and locality, so extreme variations are normal. In
the summer, colonies managed by a beekeeper may consist of 40,000 to 60,000 adult
bees (2 to 3 times that of feral colonies). These will likely be distributed among
the three castes as follows: 1 queen, 100 to 300 drones (up to 10,000 drones have
been reported), 13,300 to 20,000 foraging workers, and 26,600 to 40,000 workers
engaged in various hive duties such as brood rearing, comb construction, housecleaning,
defense, and temperature regulation. The brood (eggs and young) in a typical colony
includes 5,000 to 7,000 eggs, 7,000 to 11,000 larvae being fed, and 16,000 to
24,000 pupae in sealed cells. A single worker larva is fed approximately 1,300
meals per day for 5 days and grows to 300 times its original weight before pupation
ensues (human growth is only 10 to 20 times original body weight). Three-fourths
of a larva's weight is made up of fat. During brood rearing, the temperature of
the brood nest is maintained at 32-35'C (90-95'F), usually 33-34'C (92-93'F).
Since worker bees metabolize honey to generate the heat needed to warm the hive,
honey must be present in the hive at all times. Colony humidity is also relatively
constant at 48-50 +-6 6 percent relative humidity. To accomplish this bees gather
water and evaporate it in the hive when atmospheric humidity in the hive is low.
However, most hive humidity, including that needed for cooling, is derived from
the water content of nectar and from bee metabolism. When ambient relative humidity
is high the bees are apparently able, by some means, to maintain a lower level
in the hive. Bee behavior is instinctive and genetically pro- grammed. Yet bees
have plasticity in their central nervous system, as exhibited by their well-developed
ability to learn and remember. Bees can learn in most sensory modalities (i.e.,
distance, sight, smell, taste, and touch). There is some evidence of a rudimentary
ability to reason, such as associating flower type with reward. Bees are opportunists,
as well, exploiting the most lucrative floral sources to save time and energy.
Nevertheless, habituation (training) is an important part of bee behavior; bees
can become accustomed to such things as frequent manipulation by beekeepers or
the presence of floral sources. Bees have evolved with numerous highly specialized
sensory receptors that are unevenly distributed over the head, thorax, and abdomen.
In function, the head is principally sensory for sight, smell, taste, and touch.
The main portion of the brain within is a coalescence of three ganglia (nerve
centers) that process much of the sensory information and initiate appropriate
behavioral patterns. The thorax, tightly packed with well-innervated muscles,
is the locomotory center for flight, walking, and sound production. The feet and
legs are believed to bear important taste and touch receptors, as well. Certainly,
the ability to build hexagonal wax cells of uniform size is dependent in part
on sensory receptors on the legs. In the abdomen are found digestive, circulatory,
reproductive, and defensive organs, along with the wax glands. Nerve and respiratory
systems are distributed throughout the body. Since the insect is encased in a
hard exoskeleton, it must of necessity have specialized external sensory areas.
The bee's numerous external sensory receptors inform the central nervous system
about the external environment, as well as about events within the body (such
as the direction in which legs and wings are moving, whether the head is up or
down, if the sting is in or out, or whether the bees is in contact with food or
forage). Honey bees communicate with one another both phonetically and kinetically.
Tonal qualities of sounds produced by bees suggest that several 14 moods" can
be communicated. The best known of their communication systems is the dance language
that provides information regarding the location of a particular source of forage.
Information in this dance includes distance, direction, and quality and quantity
of food. The recruitment dances instinctively performed by worker bees are in
fact ritualized, miniaturized versions of the foraging trip the returning bee
has just taken. The recruit bee learns and practices the trip in miniature and
then leaves on her own (rather than being led, as with other social insects) to
the source. Several other lesserknown dances are performed by bees, and sound
production by the dancing bees is an essential part of the dance activity. Bees
also communicate via the aroma and taste of the products they bring back to the
hive, as well as by at least 31 pheromones (chemical compounds) they produce from
glands in their bodies. Honey bees have no unusual nutritional re- quirements,
only a balanced diet containing carbo- hydrates, fats, proteins, minerals, vitamins,
and water.'Even so, the logistics of honey bee foraging and food consumption are
incredible. A typical colony may use up to 100 lb pollen for brood rearing each
year; 4 million foraging trips are required to collect this quantity. A single
bee may carry up to 5 million pollen grains in a single trip. Some pollen is proba-
bly consumed, but most is mixed with small quanti- ties of honey or nectar and
possibly salivary prod- ucts and packed into cells adjacent to the brood nest
where it undergoes a chemical change to a product called bee bread. This product
is stored until consumed by adult bees for conversion into glandu- lar larval
food, a kind of "mother's milk " Bee bread is the principal food of the adult
nurse bees. This nutrient was so named by primitive man because of its bready
taste. Nurse bees eat and convert bee bread into at least two different glandular
secretions, which are then fed to bee larvae. The diets of workers, queens, and
drones are entirely dissimilar. Brood food recipes for each of the three castes
involve differing ratios of the two glandular products (each is the product of
bees of a different age); a quantity of honey is then added, the amount being
caste dependent. Cannibalism of eggs and larvae, which occurs during periods of
food scarcity, can preserve the colony by conserving vital nutritional elements.
Under ideal conditions and depending on the plant species involved, a colony may
produce 90.7 kg (200 lb) or more surplus honey. The bees visit 2.5 to 500 million
flowers for the nectar from which this quantity is produced. Approximately 3.6
kg (8 lb) honey are consumed in foraging and brood rearing to produce 0.45 kg
(1 lb) surplus. Estimates of energy consumption indicate that foraging bees get
about 11,265,100 km (7 million flight miles) to 3.8 L (1 gal) honey. Normally
bees forage no more than a 3.2- to 4.0-km (2- to 2.5-mi) radius from the hive,
covering 324 to 5062 ha (8,000 to 12,500 a) but may on occasion fly up to 16.1
km (10 mi) at a speed of 19.3 to 24 km (12 to 15 mi) per hour. The farther that
bees must fly from a colony to forage for nectar, the more fuel they burn and
the less efficient they are at producing a surplus of honey. The top speed of
a worker bee is about 29 km (18 mi) per hour. As with the production of heat mentioned
earlier, honey must be present in the hive to refuel foraging bees; without it
foraging ceases.top?
Since humans first began keeping bees, their principal aim has been the harvest
of honey. Thus beekeeping methods have been adapted to accommodate colony behavior.
Some success has been achieved in manipulation of colonies to capitalize on certain
behavioral traits, but honey bees must still be considered wild, not domesticated,
creatures, and honey a raw agricultural commodity. Ninety percent of the world's
beekeepers live in Europe, Russia, Asia, and Africa and produce 54 percent of
the world's honey by averaging 9.1 kg (20 lb) per colony. Ten percent of the world's
beekeepers live in Australia and North and South America and produce 46 percent
of the world honey crop by averaging 22.7 to 45.4 (50 to 100 lb) per colony. Some
stingless bees (not honey bees) are kept for honey production, but the number
of these colonies is comparatively small. Worldwide honey production is currently
in ex- cess of 544,320 t (600,000 tons) annually. This quantity is provided by
an estimated 50 million colonies kept by about 61/2 million beekeepers. The current
world population is around 3,500 million people, so there are approximately 500
times more honey bees than people. Honey is elaborated from the nectar of numerous
plant species but may also be produced from honeydew excretions of aphids and
scale insects). Nectars vary considerably in quality and quantity, depending on
the floral source. Similarly, honeys vary; some honey is nearly colorless (like
water), with a light, pleasing aroma, and some is as dark as crankcase oil, with
a heavy-bodied aroma. Honey from most floral sources falls between these extremes.
Bees convert nectar to honey by drying it down to a moisture content of 15 to
20 percent and by adding a salivary enzyme that changes sucrose (long-chain sugar)
into glucose and fructose (two short-chain sugars); honey is composed of sugars,
mainly fructose and glucose. Honey also contains trace amounts of minerals, enzymes,
vitamins, and colloids. Other biologically active constituents (such as hydrogen
peroxide and gluconic acid) inhibit some microbial development but accelerate
yeast growth. A limited number of plant sources yield nectar with toxic elements,
but fortunately bees either recognize and avoid these or are able to nullify their
effects. (Beekeepers avoid areas with such noxious plants.) Honey is used as a
sweetener (1 part honey 1.67 parts sugar) and in baking, baby foods, confectioneries,
cosmetics, meat packing, pharmaceuticals, and syrups, and for curing tobacco.
Honey is often used to maintain moisture as well. In times past, it was believed
to be a powerful aphrodisiac. It is served in liquid or granulated (spread) form
and in the comb; limited quantities of dried honey are now available. But for
bees, honey is the allpurpose food, essential for stores of body fat, for flight,
and in the production of heat, humidity, and wax. Other products of the hive include
pollen, brood (still eaten by some primitive cultures), propolis (bee glue), royal
jelly, venom, and of course beeswax. For making beeswax, each worker bee has four
pairs of wax glands on the underside of its r abdomen; these function best in
12- to 18-day-old bees, according to the needs of the colony. Both protein (pollen)
and carbohydrates (honey) are required to produce beeswax; 1 lb beeswax, which
contains about 450,000 wax scales, will provide enough wax to make 35,000 hexagonal
cells that can store 10 kg (22 lb) honey. Thus bees consume part of their food
(pollen and honey) for the purpose of converting it into nest structure -specifically
cells for food storage and brood rearing. It takes 2.7 to 4.5 kg (6 to 10 lb)
honey to produce 0.45 kg (1 lb) wax. Beeswax has many uses worldwide, including
the production of candles, cosmetics (the largest user-industry), electronics,
lubricants, leather and fabric preservatives, polishes, inks and paints, models
for dentistry, and beer. A large portion of the beeswax produced is recycled to
the bee industry where it is used to produce the foundation for new honeycomb
and queen cell cups. World production of beeswax exceeds 9072 t (10,000 tons)
annually. Propolis is used in the attachment of combs to the top and sides of
the hive, as well as for filling cracks, reducing the size of the hive entrance,
and embalming intruders. It is composed of plant resins gathered by worker bees,
beeswax (30 to 60 percent), balm (perhaps a glandular secretion of bees or a product
of honey bee digestion), as well as pollen and hive debris. In times past, varnishes
responsible for the tonal quality of violins and the finishes ori other fine woods
contained refined propolis. The human nutritional value of pollen and queen (royal)
and worker jelly has been of great interest throughout the world. However, there
is much doubt as to their real worth. These jellies, larval food synthesized from
the digestion of pollen and secreted by the brood food glands of worker bees,
have, like pollen, no proven attributes except as bee food. Nevertheless, both
are used in various cosmetics, lotions, and dietary supplements. According to
Greek mythology the infant Zeus, out of gratitude for the honey that sustained
him, gave the honey bee its sting for defense. Because the bee abused this power,
Zeus later decreed that the bee must die whenever the sting is used. Perhaps it
is ironic that now we have developed the means to milk venom from bees and use
this product in medicine. The collection and sale of bee venom is an increasingly
popular although extremely limited enterprise. Presently, its greatest use is
in the treatment of bee venom hypersensitivity. It is also reported as helpful
in reducing the pain caused by certain types of arthritis. Commercial beekeeping
has given rise to two additional hive products, namely, the queen and worker honey
bees. Worker bees are packaged and sold by the pound by beekeepers who are engaged
in this highly specialized form of beekeeping. Packages of worker bees and queens
are frequently delivered by the postal service. A package of bees normally contains
0.9 to 1.4 kg (2 to 3 lb) of bees plus a mated queen. Packaged bees are used for
establishing new colonies or for replacement of those lost through natural causes
or catastrophic events. The selling of honey bee queens is a highly lucrative
commercial enterprise. Queens are often advertised as being of a specific genetic
origin with certain desirable attributes. These queens are used by beekeepers
to requeen existing colonies in which the old queen is failing or was lost. Beekeepers
may also expand their businesses with the purchase of additional queens; each
new queen is installed in a new colony made by dividing an existing colony in
half (the old queen heads up the parent unit).top?
Reproduction in many plant species is a sexual process analogous to that of animals.
Pollen (equivalent to sperm) must find its way to the stigma (equivalent to the
vagina). Flower visitors, principally bees, are essential in the transfer of pollen
within and between flowers. Floral nectars and aromas attract bees and thus ensure
adequate pollination and the reproductive success of the plant. The honey bee's
most significant contribution to human dietary habits has been these pollination
activities. Without honey bees human tables and lives would be impoverished by
a general lack of fruits, vegetables, flowers, and other bee-pollinated plant
products; and the human diet would be almost wholly restricted to cereals, some
nuts, and the meat of wild animals. One of the world's estimated 20,000 to 30,000
living species of bees, the honey bee has become indispensable, humanity's greatest
and most versatile insect benefactor. More than 90 fruit, vegetable, nut, and
seed crops are partially or entirely dependent on bees for pollination, as are
numerous ornamental plants and wild flowers. The value of bee-pollinated crops
in the United States is estimated to be $100 million100 times the value of the
honey produced. These crops represent up to one-third of the human diet in many
countries. Mobile beekeepers in the United States and elsewhere can even supply
bees to farmers at the time pollination is needed. Early in the year these beekeepers
provide pollination services to growers in warm areas. They then move their hives
into the more temperate climates, following the spring weather northward (southward
in the southern hemisphere) and pollinating both orchard and field crops. When
they terminate their annual trek, they collect a final large honey crop and then
return home in the fall to prepare for another northward migration the following
year.top?
Like other animal life, honey bees are beset by a variety of threats to their
survival -disease, parasites, nest destroyers and predators. Their enemies include
other insects, mites, spiders, birds (woodpeckers, bee martins, and honey buzzards),
and mammals (bears, skunks, badgers, and baboons). The ever- present wax moth
is a particular problem; larvae of this moth destroy the wax combs of weak colonies
(and colonies kept by unwary