Bee - biology.
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Bee - biology.
I
INTRODUCTION
Bee, common name for a winged, flower-feeding insect with branched body hairs.
II
CHARACTERISTICS
Bees are dependent on pollen as a protein source and on flower nectar or oils as an energy source. Adult females collect pollen primarily to feed their larvae. The pollen
they inevitably lose in going from flower to flower is important to plants because some pollen lands on the pistils (reproductive structures) of other flowers of the same
species, resulting in cross-pollination (see Pollination). Bees are, in fact, the most important pollinating insects, and their interdependence with plants makes them an
excellent example of the type of symbiosis known as mutualism, an association between unlike organisms that is beneficial to both parties.
Most bees have specialized branched or feathery body hairs that help in the collection of pollen. Female bees, like many other hymenopterans, have a defensive sting.
Some bees produce honey from flower nectar. Honey bees and stingless bees commonly hoard large quantities of honey--a characteristic that is exploited by
beekeepers, who harvest the honey for human consumption (see Beekeeping).
There are about 20,000 species of bees worldwide. Some species may not yet have been discovered, and many are either not named or have not been well studied.
Bees are found throughout the world except at the highest altitudes, in polar regions, and on some small oceanic islands. The greatest diversity of bee species is found
in warm, arid or semiarid areas, especially in the American Southwest and Mexico. Bees range in size from tiny species only 2 mm (0.08 in) in length to rather large
insects up to 4 cm (1.6 in) long. Many bees are black or gray, but others are bright yellow, red, or metallic green or blue.
III
SOCIAL STRUCTURE AND NESTING HABITS
Bees have diverse nesting and social habits. This diversity has provided scientists with a natural laboratory for the study of evolution and social behavior in insects (see
Sociobiology).
A
Solitary Bees
The primitive bees, like their relatives the wasps, are solitary. Each female makes her own burrow, in which she constructs earthen chambers to contain her young. She
deposits pollen moistened with nectar or oil into individual cells until enough food has accumulated to provide for the young bee from egg hatching until the larva
reaches full size. She then lays an egg on the pollen mass and seals the cell before going on to construct another cell.
B
Social Bees
Some bees are communal. They are like solitary bees except that several females of the same generation use the same nest, each making her own cells for housing her
eggs, larvae, and pupae. A few kinds of bees are semisocial--they live in small colonies of two to seven bees of the same generation, one of which is the queen, or
principal egg layer; the others are worker bees. About 1000 species of bees live in small colonies consisting of a queen and a few daughter workers. In these colonies,
the differences in appearance and behavior between workers and queens are scarcely distinguishable. Such species, called primitively eusocial, form temporary colonies
that die out in autumn, and only the fertilized queens survive the winter. Bumblebees are familiar examples.
The eusocial, or truly social, bees live in large colonies consisting of females of two overlapping generations: mothers (queens) and daughters (workers). Males, called
drones, play no part in the colony's organization and only mate with the queens. Larvae are fed progressively--that is, cells are opened as necessary or are left open so
that workers can tend the larvae. Highly eusocial bees, a few hundred species, form permanent colonies in which the queen and worker castes are markedly different in
structure, each specialized for its own activities and unable to survive without the other. Colonies of eusocial bees are complex, highly coordinated societies. Individual
bees may have highly specialized functions within the colony. The tasks of defense, food collection and storage, reproduction, and many other activities are regulated by
the colony's response to environmental conditions inside and outside the hive. Individuals communicate by means of chemical messages, touch, sound, and, in the case
of honey bees, a symbolic dance language (to learn more about chemical communication, See Pheromone). The nests of many eusocial bees are very elaborate and
may be constructed partially of wax secreted by the bees.
C
Parasitic Bees
Parasitic, or cuckoo, bees are those that do not forage or make nests themselves but use the nests and food of other species of bees to provide for their parasitic
young. Parasitic bees are of two types: cleptoparasitic bees and social parasites. Cleptoparasitic bees invade the nests of solitary bees, hide their eggs in the brood
chambers before the hosts lay theirs, and close the chambers. The young of the parasitic bees then feed on the food that was stored in the chamber by the host
female. The eggs or young larvae of the host bee are killed either by the parasitic female or by her larvae. Social parasites are bees that kill the resident queen, lay
their own eggs in the host's cells, and then force the host's workers to raise the young parasitic bees. Females of parasitic bees lack such special features as pollen
baskets or pollen brushes since they do not forage for food for their young.
IV
FAMILIES
There are 11 families of bees (see Classification). Scientists distinguish between them by subtle differences in wing veins and by the fine structure of the mouthparts
and other microscopic characteristics. However, the bees in each family have other interesting descriptive features, including their size, nesting and foraging behaviors,
and easy-to-see body features such as body hair, the length of the tongue, and the form of the pollen-carrying structure.
Cellophane bees are relatively hairless bees with short, forked tongues. They resemble wasps more so than other bees; hence they are considered the most primitive
bees. They line their nest tunnels and larval cells (chambers for the young) with a secretion that hardens into a cellophane-like membrane. They carry pollen on leg
hairs or internally in a stomachlike crop. Mining bees are a large group of bees that make soil nests of many branching chambers, each ending in one or more cells.
They are either solitary or communal, living in separate but nearby nests. They carry pollen on body and leg hairs.
Sweat bees are generally small, dark-colored bees with little hair. They, too, usually nest in the ground but may live in societies in which related individuals help each
other. Pollen is carried on brushy areas near the base of the legs and on body hairs. Leafcutter bees and mason bees belong to a family of long-tongued bees that have
specialized pollen-carrying hairs on the underside of the abdomen. They often make their nests in preexisting cavities and may live in groups of individual nests. Some
are used in agriculture to pollinate crops. Digger bees are fast-flying, fuzzy bees that may nest in the ground solitarily or in dense clusters or may excavate nests in
wood. They have long tongues and are excellent pollinators of many plants. They carry their pollen on brushy areas near the middle of the hind leg. Carpenter bees are
also in the digger bee family.
The most familiar bees are the honey bees and their close relatives. In this family are bees that make intricate nests and live in complex societies. The pollen-carrying
structure in these bees is a smooth, bristle-surrounded area on one segment of the hind leg. This structure is known as a pollen basket, or corbicula. This group is
divided into four tribes: the orchid bees, the bumblebees, the stingless bees, and the honey bees.
Scientific classification: Bees make up a superfamily known as the Apoidea. Cellophane bees make up the family Colletidae, mining bees make up the family
Andrenidae, sweat bees make up the family Halictidae, the leafcutter and mason bees and their relatives make up the family Megachilidae, the digger bees make up the
family Anthophoridae, and honey bees and their relatives make up the family Apidae.
Contributed By:
Charles D. Michener
Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.
Bee - biology.
I
INTRODUCTION
Bee, common name for a winged, flower-feeding insect with branched body hairs.
II
CHARACTERISTICS
Bees are dependent on pollen as a protein source and on flower nectar or oils as an energy source. Adult females collect pollen primarily to feed their larvae. The pollen
they inevitably lose in going from flower to flower is important to plants because some pollen lands on the pistils (reproductive structures) of other flowers of the same
species, resulting in cross-pollination (see Pollination). Bees are, in fact, the most important pollinating insects, and their interdependence with plants makes them an
excellent example of the type of symbiosis known as mutualism, an association between unlike organisms that is beneficial to both parties.
Most bees have specialized branched or feathery body hairs that help in the collection of pollen. Female bees, like many other hymenopterans, have a defensive sting.
Some bees produce honey from flower nectar. Honey bees and stingless bees commonly hoard large quantities of honey--a characteristic that is exploited by
beekeepers, who harvest the honey for human consumption (see Beekeeping).
There are about 20,000 species of bees worldwide. Some species may not yet have been discovered, and many are either not named or have not been well studied.
Bees are found throughout the world except at the highest altitudes, in polar regions, and on some small oceanic islands. The greatest diversity of bee species is found
in warm, arid or semiarid areas, especially in the American Southwest and Mexico. Bees range in size from tiny species only 2 mm (0.08 in) in length to rather large
insects up to 4 cm (1.6 in) long. Many bees are black or gray, but others are bright yellow, red, or metallic green or blue.
III
SOCIAL STRUCTURE AND NESTING HABITS
Bees have diverse nesting and social habits. This diversity has provided scientists with a natural laboratory for the study of evolution and social behavior in insects (see
Sociobiology).
A
Solitary Bees
The primitive bees, like their relatives the wasps, are solitary. Each female makes her own burrow, in which she constructs earthen chambers to contain her young. She
deposits pollen moistened with nectar or oil into individual cells until enough food has accumulated to provide for the young bee from egg hatching until the larva
reaches full size. She then lays an egg on the pollen mass and seals the cell before going on to construct another cell.
B
Social Bees
Some bees are communal. They are like solitary bees except that several females of the same generation use the same nest, each making her own cells for housing her
eggs, larvae, and pupae. A few kinds of bees are semisocial--they live in small colonies of two to seven bees of the same generation, one of which is the queen, or
principal egg layer; the others are worker bees. About 1000 species of bees live in small colonies consisting of a queen and a few daughter workers. In these colonies,
the differences in appearance and behavior between workers and queens are scarcely distinguishable. Such species, called primitively eusocial, form temporary colonies
that die out in autumn, and only the fertilized queens survive the winter. Bumblebees are familiar examples.
The eusocial, or truly social, bees live in large colonies consisting of females of two overlapping generations: mothers (queens) and daughters (workers). Males, called
drones, play no part in the colony's organization and only mate with the queens. Larvae are fed progressively--that is, cells are opened as necessary or are left open so
that workers can tend the larvae. Highly eusocial bees, a few hundred species, form permanent colonies in which the queen and worker castes are markedly different in
structure, each specialized for its own activities and unable to survive without the other. Colonies of eusocial bees are complex, highly coordinated societies. Individual
bees may have highly specialized functions within the colony. The tasks of defense, food collection and storage, reproduction, and many other activities are regulated by
the colony's response to environmental conditions inside and outside the hive. Individuals communicate by means of chemical messages, touch, sound, and, in the case
of honey bees, a symbolic dance language (to learn more about chemical communication, See Pheromone). The nests of many eusocial bees are very elaborate and
may be constructed partially of wax secreted by the bees.
C
Parasitic Bees
Parasitic, or cuckoo, bees are those that do not forage or make nests themselves but use the nests and food of other species of bees to provide for their parasitic
young. Parasitic bees are of two types: cleptoparasitic bees and social parasites. Cleptoparasitic bees invade the nests of solitary bees, hide their eggs in the brood
chambers before the hosts lay theirs, and close the chambers. The young of the parasitic bees then feed on the food that was stored in the chamber by the host
female. The eggs or young larvae of the host bee are killed either by the parasitic female or by her larvae. Social parasites are bees that kill the resident queen, lay
their own eggs in the host's cells, and then force the host's workers to raise the young parasitic bees. Females of parasitic bees lack such special features as pollen
baskets or pollen brushes since they do not forage for food for their young.
IV
FAMILIES
There are 11 families of bees (see Classification). Scientists distinguish between them by subtle differences in wing veins and by the fine structure of the mouthparts
and other microscopic characteristics. However, the bees in each family have other interesting descriptive features, including their size, nesting and foraging behaviors,
and easy-to-see body features such as body hair, the length of the tongue, and the form of the pollen-carrying structure.
Cellophane bees are relatively hairless bees with short, forked tongues. They resemble wasps more so than other bees; hence they are considered the most primitive
bees. They line their nest tunnels and larval cells (chambers for the young) with a secretion that hardens into a cellophane-like membrane. They carry pollen on leg
hairs or internally in a stomachlike crop. Mining bees are a large group of bees that make soil nests of many branching chambers, each ending in one or more cells.
They are either solitary or communal, living in separate but nearby nests. They carry pollen on body and leg hairs.
Sweat bees are generally small, dark-colored bees with little hair. They, too, usually nest in the ground but may live in societies in which related individuals help each
other. Pollen is carried on brushy areas near the base of the legs and on body hairs. Leafcutter bees and mason bees belong to a family of long-tongued bees that have
specialized pollen-carrying hairs on the underside of the abdomen. They often make their nests in preexisting cavities and may live in groups of individual nests. Some
are used in agriculture to pollinate crops. Digger bees are fast-flying, fuzzy bees that may nest in the ground solitarily or in dense clusters or may excavate nests in
wood. They have long tongues and are excellent pollinators of many plants. They carry their pollen on brushy areas near the middle of the hind leg. Carpenter bees are
also in the digger bee family.
The most familiar bees are the honey bees and their close relatives. In this family are bees that make intricate nests and live in complex societies. The pollen-carrying
structure in these bees is a smooth, bristle-surrounded area on one segment of the hind leg. This structure is known as a pollen basket, or corbicula. This group is
divided into four tribes: the orchid bees, the bumblebees, the stingless bees, and the honey bees.
Scientific classification: Bees make up a superfamily known as the Apoidea. Cellophane bees make up the family Colletidae, mining bees make up the family
Andrenidae, sweat bees make up the family Halictidae, the leafcutter and mason bees and their relatives make up the family Megachilidae, the digger bees make up the
family Anthophoridae, and honey bees and their relatives make up the family Apidae.
Contributed By:
Charles D. Michener
Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.
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