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Bee

2007 Schools Wikipedia Selection. Related subjects: Insects, Reptiles and
Fish

                   iBees
   Osmia ribifloris
   Osmia ribifloris
         Scientific classification

   Kingdom:     Animalia
   Phylum:      Arthropoda
   Class:       Insecta
   Order:       Hymenoptera
   Suborder:    Apocrita
   (unranked)   Anthophila ( = Apiformes)
   Superfamily: Apoidea

                                  Families

   Andrenidae
   Apidae
   Colletidae
   Halictidae
   Megachilidae
   Melittidae
   Stenotritidae
   Bee collecting pollen
   Enlarge
   Bee collecting pollen

   Bees (a monophyletic lineage within the superfamily Apoidea, presently
   classified by the unranked taxon name Anthophila) are flying insects,
   closely related to wasps and ants. There are approximately 25,000
   species of bees, and they may be found on every continent except
   Antarctica. Bees are adapted for feeding on nectar and pollen, the
   former primarily as an energy source, and the latter primarily for
   protein and other nutrients. Most pollen is used as food for larvae.

   Bees have a long proboscis that enables them to obtain the nectar from
   flowers. Bees have antennae almost universally made up of thirteen
   segments in males and twelve in females. They all have two pairs of
   wings, the back pair being the smaller of the two; in a very few
   species, one sex or caste has relatively short wings that make flight
   difficult or impossible.

   Many species of bees are poorly known. The smallest bee is the dwarf
   bee (Trigona minima) and it is about 2.1 mm (5/64") long. The largest
   bee in the world is Megachile pluto, which can be as large as 39 mm
   (1.5"). The most common type of bee in North America are the many
   species of Halictidae, or sweat bees, though this may come as a
   surprise to natives, as they are so small and often mistaken for wasps
   or flies.

Pollination

   Bees play an important role in pollinating flowering plants, and are
   the major type of pollinators in ecosystems that contain flowering
   plants. Bees may focus on gathering nectar or on gathering pollen,
   depending on their greater need at the time. Bees gathering nectar may
   accomplish pollination, but bees that are deliberately gathering pollen
   are more efficient pollinators. It is estimated that one third of the
   human food supply depends on insect pollination, most of this
   accomplished by bees.

   Most bees are fuzzy and carry an electrostatic charge, thus aiding in
   the adherence of pollen. Female bees periodically stop foraging and
   groom themselves to pack the pollen into the scopa, which is on the
   legs in most bees, and on the ventral abdomen on others, and modified
   into specialized pollen baskets on the legs of honey bees and their
   relatives. Many bees are opportunistic foragers, and will gather pollen
   from a variety of plants, but many others are oligolectic, gathering
   pollen from only one or a few types of plant. A small number of plants
   produce nutritious floral oils rather than pollen, which are gathered
   and used by oligolectic bees. One small subgroup of stingless bees
   (called " vulture bees") is specialized to feed on carrion, and these
   are the only bees that do not use plant products as food. Pollen and
   nectar are usually combined together to form a "provision mass", which
   is often soupy, but can be firm. It is formed into various shapes
   (typically spheroid), and stored in a small chamber (a "cell"), with
   the egg deposited on the mass. The cell is typically sealed after the
   egg is laid, and the adult and larva never interact directly (a system
   called "mass provisioning").

   Bees are extremely important as pollinators in agriculture, especially
   the domesticated Western honey bee, with contract pollination having
   overtaken the role of honey production for beekeepers in many
   countries. Monoculture and pollinator decline have increasingly caused
   honey bee keepers to become migratory so that bees can be concentrated
   in areas of pollination need at the appropriate season. Many other
   species of bees are increasingly cultured and used to meet the
   agricultural pollination need. Bees also play a major, though not
   always understood, role in providing food for birds and wildlife. Many
   of these bees survive in refuge in wild areas away from agricultural
   spraying, only to be poisoned in massive spray programs for mosquitoes,
   gypsy moths, or other pest insects.

   Visiting flowers is a dangerous occupation with high mortality rates.
   Many assassin bugs and crab spiders hide in flowers to capture unwary
   bees. Others are lost to birds in flight. Insecticides used on blooming
   plants can kill large numbers of bees, both by direct poisoning and by
   contamination of their food supply. A honey bee queen may lay 2000 eggs
   per day during spring buildup, but she also must lay 1000 to 1500 eggs
   per day during the foraging season, simply to replace daily casualties.

   The population value of bees depends partly on the individual
   efficiency of the bees, but also on the population. Thus, while
   bumblebees have been found to be about ten times more efficient
   pollinators on cucurbits, the total efficiency of a colony of honey
   bees is much greater, due to greater numbers. Likewise, during early
   spring orchard blossoms, bumblebee populations are limited to only a
   few queens, thus they are not significant pollinators of early fruit.

Bee evolution

   Bees, like ants, are essentially a highly specialized form of wasp. The
   ancestors of bees were wasps in the family Crabronidae, and therefore
   predators of other insects. The switch from insect prey to pollen may
   have resulted from the consumption of prey insects that were flower
   visitors and were partially covered with pollen when they were fed to
   the wasp larvae. This same evolutionary scenario has also occurred
   within the vespoid wasps, where the group known as " pollen wasps" also
   evolved from predatory ancestors. The oldest bee fossil, of the genus
   Melittosphex, is 100 million years old and supports the theory that
   bees evolved from wasps . Other partial fossil evidence show that they
   evolved alongside flowers, at least 140 million years ago .

   The earliest animal pollinated flowers were pollinated by insects such
   as beetles, so the syndrome of insect pollination was well established
   before bees first appeared. The novelty is that bees are specialized as
   pollination agents, with behavioural and physical modifications that
   specifically enhance pollination, and are much more efficient at the
   task than beetles, flies, butterflies, pollen wasps, or any other
   pollinating insect. The appearance of such floral specialists is
   believed to have driven the adaptive radiation of the angiosperms, and,
   in turn, the bees themselves.

Eusocial and semisocial bees

   Bees vary tremendously in size. Here a tiny halictid bee is gathering
   pollen, while a giant bumblebee behind her gathers nectar from a lily.
   Enlarge
   Bees vary tremendously in size. Here a tiny halictid bee is gathering
   pollen, while a giant bumblebee behind her gathers nectar from a lily.

   Bees may be solitary or may live in various types of communities. The
   most advanced of these are eusocial colonies found among the honeybees,
   bumblebees, and stingless bees. Sociality is believed to have evolved
   separately many times within the bees.

   In some species, groups of cohabiting females may be sisters, and if
   there is a division of labor within the group, then they are considered
   semisocial.

   If, in addition to a division of labor, the group consists of a mother
   and her daughters, then the group is called eusocial. The mother is
   considered the "queen" and the daughters are "workers". These castes
   may be purely behavioural alternatives, in which case the system is
   considered "primitively eusocial" (similar to many paper wasps), and if
   the castes are morphologically discrete, then the system is "highly
   eusocial".

   There are many more species of primitively eusocial bees than highly
   eusocial bees, but they have been rarely studied. The biology of most
   such species is almost completely unknown. The vast majority are in the
   family Halictidae, or "sweat bees". Colonies are typically small, with
   a dozen or fewer workers, on average. The only physical difference
   between queens and workers is average size, if they differ at all. Most
   species have a single season colony cycle, even in the tropics, and
   only mated females (future queens, or "gynes") hibernate (called
   diapause). A few species have long active seasons and attain colony
   sizes in the hundreds. The orchid bees include a number of primitively
   eusocial species with similar biology. Certain species of allodapine
   bees (relatives of carpenter bees) also have primitively eusocial
   colonies, with unusual levels of interaction between the adult bees and
   the developing brood. This is "progressive provisioning"; a larva's
   food is supplied gradually as it develops. This system is also seen in
   honey bees and some bumblebees.

   Highly eusocial bees live in colonies. Each colony has a single queen,
   together with workers and, at certain stages in the colony cycle,
   drones. When humans provide a home for a colony, the structure is
   called a hive. A honey bee hive can contain up to 40,000 bees at their
   annual peak, which occurs in the spring, but usually have fewer.

Bumblebees

   Bumblebee
   Enlarge
   Bumblebee

   Bumblebees (Bombus terrestris, B. pratorum, et al.) are eusocial in a
   manner quite similar to the eusocial Vespidae such as hornets. The
   queen initiates a nest on her own (unlike queens of honeybees and
   stingless bees which start nests via swarms in the company of a large
   worker force). Bumblebee colonies typically have from 50 to 200 bees at
   peak population, which occurs in mid to late summer. Nest architecture
   is simple, limited by the size of the nest cavity (pre-existing), and
   colonies are rarely perennial. Bumblebee queens sometimes seek winter
   safety in honeybee hives, where they are sometimes found dead in the
   spring by beekeepers, presumably stung to death by the honeybees. It is
   unknown whether any survive winter in such an environment.

Stingless bees

   Stingless bees are very diverse in behaviour, but all are highly
   eusocial. They practice mass provisioning, complex nest architecture,
   and perennial colonies.

Honey bees

   The true honey bees (genus Apis) have arguably the most complex social
   behaviour among the bees. The European honey bee, Apis mellifera is the
   best known bee species and one of the best known of all insects.

Africanized honey bee

   Africanized bees, also called killer bees, are a hybrid strain of Apis
   mellifera derived from experiments to cross European and African honey
   bees by Warwick E. Kerr. Several queen bees escaped his laboratory in
   South America and have spread throughout the Americas. Africanized
   honey bees are more defensive than European honey bees.

Solitary and communal bees

   Most other bees, including familiar species of bee such as the Eastern
   carpenter bee ( Xylocopa virginica), alfalfa leafcutter bee ( Megachile
   rotundata), orchard mason bee (Osmia lignaria) and the hornfaced bee (
   Osmia cornifrons) are solitary in the sense that every female is
   fertile, and typically inhabits a nest she constructs herself. There
   are no worker bees for these species. Solitary bees typically produce
   neither honey nor beeswax. They are immune from acarine and Varroa
   mites, but have their own unique parasites, pests and diseases. (See
   diseases of the honeybee.)
   Honey Bee collecting nectar from small flowers. Location: McKinney,
   Texas.
   Enlarge
   Honey Bee collecting nectar from small flowers. Location: McKinney,
   Texas.

   Solitary bees are important pollinators, as pollen is gathered for
   provisioning the nest with food for their brood. Often it is mixed with
   nectar to form a paste-like consistency. Many solitary bees have very
   advanced types of pollen carrying structures on their bodies. Most
   solitary bees are wild, with a few species being increasingly cultured
   for pollination.

   Solitary bees are often oligoleges, in that they only visit one or more
   species of plant (unlike honeybees and bumblebees which are
   generalists). In a few cases only one species of bee can pollinate a
   plant species, and some plants are endangered because their pollinator
   is dying off.

   Solitary bees create nests in hollow reeds, holes in wood, or, most
   commonly, in tunnels in the ground. The female typically creates a
   compartment (a "cell") with an egg and some provisions for the
   resulting larva, then seals it off. A nest may consist of numerous
   cells. When the nest is in wood, usually the last (those closer to the
   entrance) contain eggs that will become males. The adult does not
   provide care for the brood and usually dies after making one or more
   nests. The males typically emerge first and are ready for mating when
   the females emerge. Providing nest boxes for solitary bees is
   increasingly popular for gardeners. Solitary bees are either stingless
   or very unlikely to sting (only in self defense).

   While solitary females each make individual nests, some species are
   gregarious, preferring to make nests near others of the same species,
   giving the appearance to the casual observer that they are social.

   In some species, multiple females share a common nest, but each makes
   and provisions her own cells independently. This type of group is
   called "communal" and is not uncommon. The primary advantage appears to
   be that a nest entrance is easier to defend when there are multiple
   females using that same entrance on a regular basis.

Cleptoparasitic bees

   Cleptoparasitic bees, commonly called "cuckoo bees" because their
   behaviour is similar to cuckoo birds, occur in several bee families,
   though the name is technically best applied to the apid subfamily
   Nomadinae. Females of these bees lack pollen collecting structures (the
   scopa) and do not construct their own nests. They typically enter the
   nests of pollen collecting species, and lay their eggs in cells
   provisioned by the host bee. When the cuckoo bee larva hatches it
   consumes the host larva's pollen ball, and if the female cleptoparasite
   has not already done so, kills and eats the host larva. In a few cases
   where the hosts are social species, the cleptoparasite remains in the
   host nest and lays many eggs, sometimes even killing the host queen and
   replacing her.

   Many cleptoparasitic bees are closely related to, and resemble, their
   hosts (i.e., the subgenus Psithyrus, which are parasitic bumble bees
   that infiltrate nests of species in the subgenus Bombus). This common
   pattern gave rise to the ecological principle known as " Emery's Rule".
   Others parasitize bees in different families, like Townsendiella, a
   nomadine apid, one species of which is a cleptoparasite of the melittid
   genus Hesperapis, while the other species in the same genus attack
   halictid bees.

Gallery

   Honeybee on a Sphaeralcea flower. Mesa, Az

   Honeybee in a Sphaeralcea flower. Mesa, Az

   Sweat bee, Agapostemon virescens (female) on a Coreopsis flower.
   Madison, Wi

   Bumblebee, Bombus sp. startles Agapostemon virescens. Madison, Wi

   Bumblebee, Bombus sp. on a Coreopsis flower. Madison, Wi

   Retrieved from " http://en.wikipedia.org/wiki/Bee"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
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