Gobi Desert

From Wikipedia, the free encyclopedia

Gobi Desert (Говь)
Desert
Gobi Desert landscape in Ömnögovi Province, Mongolia
Countries	Mongolia, China
Mongolian Aimags	Bayankhongor, Dornogovi, Dundgovi, Govi-Altai, Govisümber, Ömnögovi, Sükhbaatar
Chinese Autonomous Region	Inner Mongolia
Landmark	Nemegt Basin
Length	1,500 km (932 mi), SE/NW
Width	800 km (497 mi), N/S
Area	1,295,000 km2 (500,002 sq mi)
The Gobi Desert lies in the territory of the People's Republic of China and Mongolia.

The Gobi (/ˈɡoʊ.bi/; Mongolian: Говь, Govi, "semidesert"; Chinese: 戈壁; pinyin: Gēbì ) is a large desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia. The desert basins of the Gobi are bounded by the Altai Mountains and the grasslands and steppes of Mongolia on the north, by the Taklamakan Desert to the West, by the Hexi Corridor and Tibetan Plateau to the southwest, and by the North China Plain to the southeast. The Gobi is most notable in history as part of the great Mongol Empire, and as the location of several important cities along the Silk Road.

The Gobi is made up of several distinct ecological and geographic regions based on variations in climate and topography. One is the Eastern Gobi desert steppe ecoregion, a palearctic ecoregion in the deserts and xeric shrublands biome, home to the Bactrian camel and various other animals.^[1] It is a rain shadow desert formed by the Himalaya range blocking rain-carrying clouds from the Indian Ocean from reaching the Gobi territory.

Geography

The Gobi measures over 1,600 km (1,000 mi) from southwest to northeast and 800 km (500 mi) from north to south. The desert is widest in the west, along the line joining the Lake Bosten and the Lop Nor (87°-89° east). It occupies an arc of land 1,295,000 km² (500,000 sq mi)^[2] in area as of 2007; it is the fifth-largest desert in the world and Asia's largest. Much of the Gobi is not sandy but has exposed bare rock.

The Gobi has several different Chinese names, including 沙漠 (Shāmò, a generic term for deserts) and 瀚海 (Hànhǎi, "endless sea"). In its broadest definition, the Gobi includes the long stretch of desert and semi-desert area extending from the foot of the Pamirs, 77° east, to the Greater Khingan Mountains, 116°-118° east, on the border of Manchuria; and from the foothills of the Altay, Sayan, and Yablonoi mountain ranges on the north to the Kunlun, Altyn-Tagh, and Qilian mountain ranges, which form the northern edges of the Tibetan Plateau, on the south.^{[citation needed]}

Gobi desert near Dunhuang

A relatively large area on the east side of the Greater Khingan range, between the upper waters of the Songhua (Sungari) and the upper waters of the Liao-ho, is reckoned to belong to the Gobi by conventional usage. Some geographers and ecologists prefer to regard the western area of the Gobi region (as defined above): the basin of the Tarim in Xinjiang and the desert basin of Lop Nor and Hami (Kumul), as forming a separate and independent desert, called the Taklamakan Desert.

Archeologists and paleontologists have done excavations in the Nemegt Basin in the northwestern part of the Gobi Desert (in Mongolia), which is noted for its fossil treasures, including early mammals, dinosaur eggs, and prehistoric stone implements, some 100,000 years old.^{[citation needed]}

Climate

Gobi by NASA World Wind

Sand dunes in Inner Mongolia Autonomous Region, China

A summer monsoon produces a flash flood, 2005

Bactrian camels by the sand dunes of Khongoryn Els, Gurvansaikhan NP, Mongolia.

The sand dunes of Khongoryn Els, Gurvansaikhan NP, Mongolia

The Gobi is a cold desert, with frost and occasionally snow occurring on its dunes. Besides being quite far north, it is also located on a plateau roughly 910–1,520 metres (2,990–4,990 ft) above sea level, which contributes to its low temperatures. An average of approximately 194 millimetres (7.6 in) of rain falls annually in the Gobi. Additional moisture reaches parts of the Gobi in winter as snow is blown by the wind from the Siberian Steppes. These winds cause the Gobi to reach extremes of temperature ranging from –40°C (–40°F) in winter to +50°C (122°F) in summer.^[3]

The climate of the Gobi is one of great extremes, combined with rapid changes of temperature of as much as 35 °C (63 °F). These can occur not only seasonally but within 24 hours.

Temperature

	Sivantse (1190 m)	Ulaanbaatar (1150 m)
Annual mean	−2.5 °C (27.5 °F)	2.8 °C (37.0 °F)
January mean	−26.5 °C (−15.7 °F)	−16.5 °C (2.3 °F)
July mean	17.5 °C (63.5 °F)	19.0 °C (66.2 °F)
Extremes	−43 to 38 °C (−45 to 100 °F)	−47 to 38.6 °C (−53 to 101 °F)

In southern Mongolia, the temperature has been recorded as low as −32.8 °C (−27.0 °F). In contrast, in Alxa, Inner Mongolia, it rises as high as 37 °C (99 °F) in July.

Average winter minimums are a frigid −40 °C (−40 °F) while summertime temperatures are warm to hot, with highs that range up to 50 °C (122 °F). Most of the precipitation falls during the summer.

Although the southeast monsoons reach the southeast parts of the Gobi, the area throughout this region is generally characterized by extreme dryness, especially during the winter, when the Siberian anticyclone is at its strongest. Hence, the icy sandstorms and snowstorms of spring and early summer plus early January (winter)

Conservation, ecology, and economy

The Gobi Desert is the source of many important fossil finds, including the first dinosaur eggs.

Despite the harsh conditions, these deserts and the surrounding regions sustain many animals, including black-tailed gazelles, marbled polecats, bactrian camels, Mongolian wild ass and sandplovers. They are occasionally visited by snow leopards, brown bears, and wolves. Drought-adapted shrubs in the desert included gray sparrow's saltwort, gray sagebrush, and low grasses such as needle grass and bridlegrass. Several large nature reserves have been established in the Gobi, including Gobi Gurvansaikhan National Park, Great Gobi A and Great Gobi B Strictly Protected Area.

The area is vulnerable to trampling by livestock and off-road vehicles (effects from human intervention are greater in the eastern Gobi Desert, where rainfall is heavier and may sustain livestock). In Mongolia, grasslands have been degraded by goats, which are raised by nomadic herders as source of cashmere wool. The economic trends of livestock privatization and the collapse of the urban economy have caused people to return to subsistence rural lifestyles, away from urbanization.

Large copper and gold deposits located at Oyuu Tolgoi, about 80 kilometers from the Chinese border into Mongolia, are being investigated for development as mining operations.^[4] The Oyu Tolgoi copper and gold mine, under construction by Rio Tinto in the South Gobi Desert, is expected to begin operation in early 2013, and is the biggest economic undertaking in the country's history. Rio Tinto estimates that taxes, royalties and dividends generated by the Oyu Tolgoi project is expected to add a third to the country's gross domestic product by 2020. Rio Tinto forecasts average annual production of 450,000 tonnes of copper and 330,000 ounces of gold, and with 1.4 billion tonnes of reserves and a resource of 3.1 billion tonnes, the mine is expected to last for more than 50 years. ^[5]

The mine has been and remains controversial. There is significant opposition in Mongolia's parliament to the terms under which the mine will proceed, and some are calling for the terms to be renegotiated. Specifically, the contention revolves primarily around the question of whether negotiations were fair (Rio Tinto is far better resourced) and whether Rio Tinto will pay adequate taxes on the revenues it derives from the mine (an agreement was reached whereby the operation will be exempt from windfall tax. ^[6]

Desertification

Currently, the Gobi desert is expanding at an alarming rate, in a process known as desertification. The expansion is particularly rapid on the southern edge into China, which has seen 3,600 km² (1,390 sq mi) of grassland overtaken every year by the Gobi Desert. Dust storms, which used to occur regularly in China, have increased in frequency in the past 20 years, mainly due to desertification. They have caused further damage to China's agriculture economy.

The expansion of the Gobi is attributed mostly to human activities, notably deforestation, overgrazing, and depletion of water resources. China has tried various plans to slow the expansion of the desert, which have met with some small degree of success, but no major effects. The most recent plan involves the planting of the Green Wall of China, a huge ring of newly planted forests; the government hopes the forests will help stabilize the soil, retain moisture, and act as a buffer against further desertification.

Ecoregions of the Gobi

The Gobi, broadly defined, can be divided into five distinct dry ecoregions.

• Eastern Gobi desert steppe, the easternmost of the Gobi ecoregions, covering an area of 281,800 km² (108,804 sq mi). It extends from the Inner Mongolian Plateau in China northward into Mongolia. It includes the Yin Mountains and many low-lying areas with salt pans and small ponds. It is bounded by the Mongolian-Manchurian grassland to the north, the Yellow River Plain to the southeast, and the Alashan Plateau semi-desert to the southeast and east.

• Alashan Plateau semi-desert, lies west and southwest of the Eastern Gobi desert steppe. It consists of the desert basins and low mountains lying between the Gobi Altai range on the north, the Helan Mountains to the southeast, and the Qilian Mountains and northeastern portion of the Tibetan Plateau on the southwest.

• Gobi Lakes Valley desert steppe, ecoregion lies north of Alashan Plateau semi-desert, between the Gobi Altai range to the south and the Khangai Mountains to the north.

• Dzungarian Basin semi-desert, includes the desert basin lying between the Altai mountains on the north and the Tian Shan range on the south. It includes the northern portion of China's Xinjiang province and extends into the southeastern corner of Mongolia. The Alashan Plateau semi-desert lies to the east, and the Emin Valley steppe to the west, on the China-Kazakhstan border.

• Tian Shan range, separates the Dzungarian Basin semi-desert from the Taklamakan Desert, which is a low, sandy desert basin surrounded by the high mountain ranges of the Tibetan Plateau to the south and the Pamirs to the west. The Taklamakan Desert ecoregion includes the Desert of Lop.

Eastern Gobi desert steppe

A Khulan (Mongolian Wild Ass) on a hill in the eastern Gobi of Mongolia at sunset.

The surface is extremely diversified, although there are no great differences in vertical elevation. Between Ulaanbaatar (48°00′N 107°00′E) and the small lake of Iren-dubasu-nor (43°45′N 111°50′E), the surface is greatly eroded. Broad flat depressions and basins are separated by groups of flat-topped mountains of relatively low elevation 150 to 180 m (490 to 590 ft)), through which archaic rocks crop out as crags and isolated rugged masses. The floors of the depressions lie mostly between 900 to 1,000 m (3,000 to 3,300 ft) above sea-level. Farther south, between Iren-dutiasu-nor and the Hwang-ho, comes a region of broad tablelands alternating with flat plains, the latter ranging at altitudes of 1000–1100 m and the former at 1,070 to 1,200 m (3,510 to 3,940 ft). The slopes of the plateaus are more or less steep, and are sometimes penetrated by "bays" of the lowlands.

As the border-range of the Hyangan is approached, the country steadily rises up to 1,370 m (4,490 ft) and then to 1,630 m (5,350 ft). Here small lakes frequently fill the depressions, though the water in them is generally salt or brackish. Both here and for 320 km (199 mi) south of Ulaanbaatar, streams are frequent and grass grows more or less abundantly. Through all the central parts, until the bordering mountains are reached, trees and shrubs are utterly absent. Clay and sand are the predominant formations; the watercourses, especially in the north, being frequently excavated 2 to 3 m (6 ft 7 in to 9 ft 10 in) deep. In many places in the flat, dry valleys or depressions farther south, beds of loess, 5 to 6 m (16 to 20 ft) thick, are exposed. West of the route from Ulaanbaatar to Kalgan, the country presents approximately the same general features, except that the mountains are not so irregularly scattered in groups but have more strongly defined strikes, mostly east to west, west-north-west to east-south-east, and west-south-west to east-north-east.

The altitudes are higher, those of the lowlands ranging from 1,000 to 1,700 m (3,300 to 5,600 ft), and those of the ranges from 200 to 500 m (660 to 1,640 ft) higher, though in a few cases they reach altitudes of 2,400 m (7,900 ft). The elevations do not form continuous chains, but make up a congeries of short ridges and groups rising from a common base and intersected by a labyrinth of ravines, gullies, glens and basins. But the tablelands, built up of the horizontal red deposits of the Han-gai (Obruchev's Gobi formation) which are characteristic of the southern parts of eastern Mongolia, are absent here or occur only in one locality, near the Shara-muren river. They are greatly intersected by gullies or dry watercourses. Water is scarce, with no streams, no lakes, no wells, and precipitation falls seldom. The prevailing winds blow from the west and northwest, and the pall of dust overhangs the country as in the Takla Makan and the desert of Lop. Characteristic of the flora are wild garlic, Kalidium gracile, wormwood, saxaul, Nitraria schoberi, Caragana, Ephedra, saltwort and the grass Lasiagrostis splendens. The taana wild onion Allium polyrrhizum is the main browse eaten by many herd animals, and Mongolians claim that this is essential to produce the correct, slightly hazelnut-like flavour of camel airag (fermented milk).

This great desert country of Gobi is crossed by several trade routes, some of which have been in use for thousands of years. Among the most important are those from Kalgan (at the Great Wall) to Ulaanbaatar (960 km (597 mi)); from Jiuquan (in Gansu) to Hami 670 km (416 mi); from Hami to Beijing (2,000 km (1,243 mi)); from Hohhot to Hami and Barkul; and from Lanzhou (in Gansu) to Hami.

Alashan Plateau semi-desert

The southwestern portion of the Gobi, known also as the Hsi-tau and the Little Gobi, fills the space between the great north loop of the Yellow River on the east, the Ejin River on the west, and the Qilian Mountains and narrow rocky chain of Longshou, 3,200 to 3,500 m (10,500 to 11,500 ft) in altitude, on the southwest. The Ordos Desert, which covers the northeastern portion of the Ordos Plateau, in the great north loop of the Huang He, is part of this ecoregion. It belongs to the middle basin of the three great depressions into which Potanin divides the Gobi as a whole.

"Topographically," says Nikolai Przhevalsky, "it is a perfectly level plain, which in all probability once formed the bed of a huge lake or inland sea." He concludes this based on the level area of the region as a whole, the hard saldgine clay and the sand-strewn surface and, lastly, the salt lakes which occupy its lowest parts. For hundreds of kilometers, nothing can be seen but bare sands; in some places they continue so far without a break that the Mongols call them Tengger (i.e. sky). These vast expanses are absolutely waterless, nor do any oases relieve the unbroken stretches of yellow sand, which alternate with equally vast areas of saline clay or, nearer the foot of the mountains, with barren shingle. Although on the whole a level country with a general altitude of 1,000 to 1,500 m (3,300 to 4,900 ft), this section, like most other parts of the Gobi, is crowned by a chequered network of hills and broken ranges going up 300 m higher. The vegetation is confined to a few varieties of bushes and a dozen kinds of grasses and herbs, the most conspicuous being saxaul (Haloxylon ammondendron) and Agriophyllum gobicum. The others include prickly convolvulus, field wormwood (Artemisia campestris), acacia, Inula ammophila, Sophora flavescens, Convolvulus ammanii, Peganum and Astragalus, but all dwarfed, deformed and starved. The fauna consists of little but antelope, wolf, fox, hare, hedgehog, marten, numerous lizards and a few birds, e.g. the sandgrouse, lark, stonechat, sparrow, crane, Henderson's Ground Jay (Podoces hendersoni), Horned Lark (Eremophila alpestris), and Crested Lark (Galerida cristata).

Dzungarian Basin semi-desert

The structure here is that of the mighty T'ien Shan, or Heavenly Mountains, running from west to east. It divides the northern one-third of Sinkiang from the southern two-thirds. On the northern side, rivers formed from the snow and glaciers of the high mountains break through barren foothill ranges and flow out into an immense, hollow plain. Here the rivers begin to straggle and fan out, and form great marshes with dense reed-beds. Westerners call this terrain the Dzungarian desert. The Chinese also call it a desert, but the Mongols call it a 'gobi'—that is, a land of thin herbage, more suitable for camels than for cows, but capable also, if herds are kept small and moved frequently, of sustaining horses, sheep, and goats. The herbage comprises a high proportion of woody, fragrant plants. Gobi mutton is the most aromatic in the world.^[7]

The Yulduz valley or valley of the Haidag-gol (43°N 83°E–43°N 86°E) is a mini desert enclosed by two prominent members of the Shanashen Trahen Osh mountain range, namely the chucis and the kracenard pine rallies, running perpendicular and far from one another. As they proceed south, they transcend and transpose, sweeping back on east and west respectively, with Lake Bosten in between. These two ranges mark the northern and the southern edges respectively of a great swelling, which extends eastward for nearly twenty degrees of longitude. On its northern side, the Chol-tagh descends steeply, and its foot is fringed by a string of deep depressions, ranging from Lukchun (130 m (427 ft) below sea level) to Hami (850 m (2,789 ft) above sea-level). To the south of the Kuruk-tagh lie the desert of Lop Nur, the Kum-tagh desert, and the valley of the Bulunzir-gol. To this great swelling, which arches up between the two border-ranges of the Chol-tagh and Kuruk-tagh, the Mongols give the name of Ghashuun-Gobi or "Salt Desert". It is some 130 to 160 km (81 to 99 mi) across from north to south, and is traversed by a number of minor parallel ranges, ridges and chains of hills. Down its middle runs a broad stony valley, 40 to 80 km (25 to 50 mi) wide, at an elevation of 900 to 1,370 m (2,950 to 4,490 ft). The Chol-tagh, which reaches an average altitude of 1,800 m (5,900 ft), is absolutely sterile, and its northern foot rests upon a narrow belt of barren sand, which leads down to the depressions mentioned above.

The Kuruk-tagh is the greatly disintegrated, denuded and wasted relic of a mountain range which formerly was of incomparably greater magnitude. In the west, between Lake Bosten and the Tarim, it consists of two, possibly of three, principal ranges, which, although broken in continuity, run generally parallel to one another, and embrace between them numerous minor chains of heights. These minor ranges, together with the principal ranges, divide the region into a series of long; narrow valleys, mostly parallel to one another and to the enclosing mountain chains, which descend like terraced steps, on the one side towards the depression of Lukchun and on the other towards the desert of Lop. In many cases these latitudinal valleys are barred transversely by ridges or spurs, generally elevations en masse of the bottom of the valley. Where such elevations exist, there is generally found, on the east side of the transverse ridge, a cauldron-shaped depression, which some time or other has been the bottom of a former lake, but is now nearly a dry salt-basin. The surface configuration is in fact markedly similar to that which occurs in the inter-mount latitudinal valleys of the Kunlun Mountains. The hydrography of the Ghashiun-Gobi and the Kuruk-tagh is determined by these chequered arrangements of the latitudinal valleys. Most of the principal streams, instead of flowing straight down these valleys, cross them diagonally and only turn west after they have cut their way through one or more of the transverse barrier ranges. To the highest range on the great swelling Grumm-Grzhimailo gives the name of Tuge-tau, its altitude being 2,700 m (8,858 ft) above the level of the sea and some 1,200 m (3,937 ft) above the crown of the swelling itself. This range he considers to belong to the Choltagh system, whereas Sven Hedin would assign it to the Kuruk-tagh. This last, which is pretty certainly identical with the range of Kharateken-ula (also known as the Kyzyl-sanghir, Sinir, and Singher Mountains), that overlooks the southern shore of the Lake Bosten, though parted from it by the drift-sand desert of Ak-bel-kum (White Pass Sands), has at first a west-northwest to east-southeast strike, but it gradually curves round like a scimitar towards the east-northeast and at the same time gradually decreases in elevation. In 91° east, while the principal range of the Kuruk-tagh system wheels to the east-northeast, four of its subsidiary ranges terminate, or rather die away somewhat suddenly, on the brink of a long narrow depression (in which Sven Hedin sees a northeast bay of the former great Central Asian lake of Lop-nor), having over against them the écheloned terminals of similar subordinate ranges of the Pe-shan (Boy-san) system (see below). The Kuruk-tagh is throughout a relatively low, but almost completely barren range, being entirely destitute of animal life, save for hares, antelopes and wild camels, which frequent its few small, widely scattered oases. The vegetation, which is confined to these same relatively favoured spots, is of the scantiest and is mainly confined to bushes of saxaul (Haloxylon), anabasis, reeds (kamish), tamarisks, poplars, and Ephedra

European exploration up to 1911

The Gobi had a long history of human habitation, mostly by nomadic peoples. By the early 20th century the region was under the nominal control of Manchu-China, and inhabited mostly by Mongols, Uyghurs, and Kazakhs. The Gobi desert as a whole was only very imperfectly known to outsiders, information being confined to the observations which individual travellers had made from their respective itineraries across the desert. Amongst the European explorers who contributed to early 20th century understanding of the Gobi, the most important were:

• Jean-François Gerbillon (1688–1698)
• Eberhard Isbrand Ides (1692–1694)
• Lorenz Lange (1727–1728 and 1736)
• Fuss and Alexander G. von Bunge (1830–1831)
• Hermann Fritsche (1868–1873)
• Pavlinov and Z.L. Matusovski (1870)
• Ney Elias (1872–1873)
• Nikolai Przhevalsky (1870–1872 and 1876–1877)
• Zosnovsky (1875)
• Mikhail V. Pevtsov (1878)
• Grigory Potanin (1877 and 1884–1886)
• Count Béla Széchenyi and Lajos Lóczy (1879–1880)
• The brothers G. E. Grumm-Grshimailo (1889–1890) and ? Grumm-Grshimailo.
• Pyotr Kuzmich Kozlov (1893–1894 and 1899–1900)
• Vsevolod I. Roborovsky (1894)
• Vladimir Obruchev (1894–1896)
• Karl Josef Futterer and Dr. Holderer (1896)
• Charles-Etienne Bonin (1896 and 1899)
• Sven Hedin (1897 and 1900–1901)
• K. Bogdanovich (1898)
• Ladyghin (1899–1900) and Katsnakov (1899–1900)

Honey bee

From Wikipedia, the free encyclopedia

Honey bees Temporal range: Oligocene–Recent PreЄ Є O S D C P T J K Pg N
European honey bee carrying pollen back to the hive
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Apidae
Subfamily:	Apinae
Tribe:	Apini Latreille, 1802
Genus:	Apis Linnaeus, 1758
Species
Subgenus Micrapis: Apis andreniformis Apis florea Subgenus Megapis: Apis dorsata Subgenus Apis: Apis cerana Apis koschevnikovi Apis mellifera Apis nigrocincta

Honey bees (or honeybees) are bees of the genus Apis, primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests from wax. Honey bees are the only extant members of the tribe Apini, all in the genus Apis. Currently, only seven species of honey bee are recognized, with a total of 44 subspecies,^[1] though historically, from six to 11 species have been recognised. Honey bees represent only a small fraction of the roughly 20,000 known species of bees.

Some other types of related bees produce and store honey, but only members of the genus Apis are true honey bees. The study of honey bees is known as apiology.

Origin, systematics and distribution

Distribution of honey bees around the world

Apis dorsata on Tribulus terrestris in Hyderabad, India

Morphology of a female honey bee

Apis dorsata on comb

Honey bees appear to have their center of origin in South and Southeast Asia (including the Philippines), as all but one (i.e. Apis mellifera), of the extant species are native to that region. Notably, living representatives of the earliest lineages to diverge (Apis florea and Apis andreniformis) have their center of origin there.^[2]

The first Apis bees appear in the fossil record at the Eocene–Oligocene boundary (23–56 Mya), in European deposits. The origin of these prehistoric honey bees does not necessarily indicate Europe as the place of origin of the genus, only that it occurred there then. A few fossil deposits are known from South Asia, the suspected region of honey bee origin, and fewer still have been thoroughly studied.

No Apis species existed in the New World during human times before the introduction of A. mellifera by Europeans. Only one fossil species is documented from the New World, Apis nearctica, known from a single 14-million-year old specimen from Nevada.^[3]

The close relatives of modern honey bees—e.g. bumblebees and stingless bees—are also social to some degree, and social behavior seems a plesiomorphic trait that predates the origin of the genus. Among the extant members of Apis, the more basal species make single, exposed combs, while the more recently evolved species nest in cavities and have multiple combs, which has greatly facilitated their domestication.

Most species have historically been cultured or at least exploited for honey and beeswax by humans indigenous to their native ranges. Only two of these species have been truly domesticated, one (A. mellifera) at least since the time of the building of the Egyptian pyramids, and only that species has been moved extensively beyond its native range.

Today's honey bees constitute three clades.^[1][4]

Genetics

The chromosome counts of female bees for the three clades are Micrapis 2N=16, Megapis 2N=16, Apis 2N=32. Drones of all species have 1N chromosome counts. The genome of Apis has been mapped.
Drones (males) are produced from unfertilized eggs, so represent only the DNA of the queen that laid the eggs, i.e. have only a mother. Workers and queens (both female) result from fertilized eggs, so have both a mother and a father. A modified form of parthenogenesis controls sex differentiation. The sex allele is polymorphic, and so long as two different variants are present, a female bee results. If both sex alleles are identical, diploid drones are produced. Honey bees detect and destroy diploid drones after the eggs hatch.

Queens typically mate with multiple drones on more than one mating flight. Once mated, they lay eggs and fertilize them as needed from sperm stored in the spermatheca. Since the number of sex alleles is limited—about 18 are known in Apis—a queen will most likely mate with one or more drones having sex alleles identical with one of the sex alleles in the queen. The queen, then, typically produces a percentage of diploid drone eggs.

Micrapis

Apis florea and Apis andreniformis are small honey bees of southern and southeastern Asia. They make very small, exposed nests in trees and shrubs. Their stings are often incapable of penetrating human skin, so the hive and swarms can be handled with minimal protection. They occur largely sympatrically, though they are very distinct evolutionarily and are probably the result of allopatric speciation, their distribution later converging. Given that A. florea is more widely distributed and A. andreniformis is considerably more aggressive, honey is, if at all, usually harvested from the former only. They are the most ancient extant lineage of honey bees, maybe diverging in the Bartonian (some 40 million years ago or slightly later) from the other lineages, but do not seem to have diverged from each other a long time before the Neogene.^[4]

Megapis

One species is recognized in the subgenus Megapis. It usually builds single or a few exposed combs on high tree limbs, on cliffs, and sometimes on buildings. They can be very fierce. Periodically robbed of their honey by human "honey hunters", colonies are easily capable of stinging a human being to death if provoked.

• Apis dorsata, the giant honey bee, is native and widespread across most of South and Southeast Asia.
  • Apis dorsata binghami, the Indonesian honey bee, is classified as the Indonesian subspecies of the giant honey bee or a distinct species; in the latter case, A. d. breviligula and/or other lineages would probably also have to be considered species.^[5]
  • Apis dorsata laboriosa, the Himalayan honey bee, was initially described as a distinct species. Later, it was included in A. dorsata as a subspecies^[1] based on the biological species concept, though authors applying a genetic species concept have suggested it should be considered a species.^[4] Essentially restricted to the Himalayas, it differs little from the giant honey bee in appearance, but has extensive behavioral adaptations that enable it to nest in the open at high altitudes despite low ambient temperatures. It is the largest living honey bee.

Apis

Eastern honey bee (Apis cerana) from Hong Kong

The eastern species include three or four species. The reddish Koschevnikov's bee (Apis koschevnikovi) from Borneo is well distinct; it probably derives from the first colonization of the island by cave-nesting honey bees. Apis cerana, the eastern honey bee proper, is the traditional honey bee of southern and eastern Asia, kept in hives in a similar fashion to A. mellifera, though on a much smaller and regionalised scale. It has not been possible yet to resolve its relationship to the Bornean A. c. nuluensis and Apis nigrocincta from the Philippines to satisfaction; the most recent hypothesis is that these are indeed distinct species, but that A. cerana is still paraphyletic, consisting of several good species.^[4]

The European honey bee originated from eastern Africa. This bee is pictured in Tanzania.

A. mellifera, the most common domesticated species, was the third insect to have its genome mapped. It seems to have originated in eastern tropical Africa and spread from there to Northern Europe and eastwards into Asia to the Tien Shan range. It is variously called the European, western or common honey bee in different parts of the world. Many subspecies have adapted to the local geographic and climatic environments; in addition, hybrid strains, such as the Buckfast bee, have been bred. Behavior, color, and anatomy can be quite different from one subspecies or even strain to another.

Regarding phylogeny, this is the most enigmatic honey bee species. It seems to have diverged from its eastern relatives only during the Late Miocene. This would fit the hypothesis that the ancestral stock of cave-nesting honey bees was separated into the western group of East Africa and the eastern group of tropical Asia by desertification in the Middle East and adjacent regions, which caused declines of food plants and trees that provided nest sites, eventually causing gene flow to cease. The diversity of subspecies is probably the product of a largely Early Pleistocene radiation aided by climate and habitat changes during the last ice age. That the western honey bee has been intensively managed by humans for many millennia – including hybridization and introductions – has apparently increased the speed of its evolution and confounded the DNA sequence data to a point where little of substance can be said about the exact relationships of many A. mellifera subspecies.^[4]

Apis mellifera is not native to the Americas, so was not present upon the arrival of the European explorers and colonists. However, other native bee species were kept and traded by indigenous peoples.^[6] In 1622, European colonists brought the dark bee (A. m. mellifera) to the Americas, followed later by Italian bees (A. m. ligustica) and others. Many of the crops that depend on honey bees for pollination have also been imported since colonial times. Escaped swarms (known as "wild" bees, but actually feral) spread rapidly as far as the Great Plains, usually preceding the colonists. Honey bees did not naturally cross the Rocky Mountains; they were transported by the Mormon pioneers^[7] to Utah in the late 1840s, and by ship to California in the early 1850s.

An Africanized bee extracts nectar from a flower as pollen grains stick to its body in Tanzania

Africanized bee

Africanized bees (known colloquially as "killer bees") are hybrids between European stock and one of the African subspecies A. m. scutellata; they are often more aggressive than and do not create as much of a surplus as European bees, but are more resistant to disease and are better foragers.^{[citation needed]} Originating by accident in Brazil, they have spread to North America and constitute a pest in some regions. However, these strains do not overwinter well, so are not often found in the colder, more northern parts of North America. The original breeding experiment for which the African bees were brought to Brazil in the first place has continued (though not as intended). Novel hybrid strains of domestic and redomesticated Africanized bees combine high resilience to tropical conditions and good yields. They are popular among beekeepers in Brazil.

Frame removed from Langstroth hive

Beekeeping

Two species of honey bee, A. mellifera and A. cerana indica, are often maintained, fed, and transported by beekeepers. Modern hives also enable beekeepers to transport bees, moving from field to field as the crop needs pollinating and allowing the beekeeper to charge for the pollination services they provide, revising the historical role of the self-employed beekeeper, and favoring large-scale commercial operations.

Colony collapse disorder

Beekeepers in Western countries have been reporting slow declines of stocks for many years, apparently due to impaired protein production, changes in agricultural practice, or unpredictable weather. In early 2007, abnormally high die-offs (30–70% of hives) of European honey bee colonies occurred in North America; such a decline seems unprecedented in recent history. This has been dubbed "colony collapse disorder" (CCD); it is unclear whether this is simply an accelerated phase of the general decline due to stochastically more adverse conditions in 2006, or a novel phenomenon. Research has so far failed to determine what causes it, but the weight of evidence is tentatively leaning towards CCD being a syndrome rather than a disease, as it seems to be caused by a combination of various contributing factors rather than a single pathogen or poison. However, in April of 2013, after a report was released by the European Food Safety Authority identifying the significant risks of the class of pesticides called neonicotinoids, the European Union called for a two-year restriction on neonicotinoid pesticides.^[8]

Lifecycle

A queen bee: a coloured dot, in this case yellow, is added to assist the beekeeper in identifying the queen.

Honey bee eggs shown in opened wax cells

Drone pupae

Emergence of a black bee (A. m. mellifera)

Eggs and larvae

As in a few other types of eusocial bees, a colony generally contains one queen bee, a fertile female; seasonally up to a few thousand drone bees or fertile males;^[9] and a large seasonally variable population of sterile female worker bees. Details vary among the different species of honey bees, but common features include:

1. Eggs are laid singly in a cell in a wax honeycomb, produced and shaped by the worker bees. Using her spermatheca, the queen actually can choose to fertilize the egg she is laying, usually depending on into which cell she is laying. Drones develop from unfertilised eggs and are haploid, while females (queens and worker bees) develop from fertilised eggs and are diploid. Larvae are initially fed with royal jelly produced by worker bees, later switching to honey and pollen. The exception is a larva fed solely on royal jelly, which will develop into a queen bee. The larva undergoes several moultings before spinning a cocoon within the cell, and pupating.

2. Young worker bees clean the hive and feed the larvae. When their royal jelly-producing glands begin to atrophy, they begin building comb cells. They progress to other within-colony tasks as they become older, such as receiving nectar and pollen from foragers, and guarding the hive. Later still, a worker takes her first orientation flights and finally leaves the hive and typically spends the remainder of her life as a forager.

3. Worker bees cooperate to find food and use a pattern of "dancing" (known as the bee dance or waggle dance) to communicate information regarding resources with each other; this dance varies from species to species, but all living species of Apis exhibit some form of the behavior. If the resources are very close to the hive, they may also exhibit a less specific dance commonly known as the "round dance".

4. Honey bees also perform tremble dances, which recruit receiver bees to collect nectar from returning foragers.

5. Virgin queens go on mating flights away from their home colony to a drone congregation area, and mate with multiple drones before returning. The drones die in the act of mating. Queen honey bees do not mate with drones from their home colony.

6. Colonies are established not by solitary queens, as in most bees, but by groups known as "swarms", which consist of a mated queen and a large contingent of worker bees. This group moves en masse to a nest site scouted by worker bees beforehand. Once they arrive, they immediately construct a new wax comb and begin to raise new worker brood. This type of nest founding is not seen in any other living bee genus, though several groups of vespid wasps also found new nests by swarming (sometimes including multiple queens). Also, stingless bees will start new nests with large numbers of worker bees, but the nest is constructed before a queen is escorted to the site, and this worker force is not a true "swarm".

Winter survival

In cold climates, honey bees stop flying when the temperature drops below about 10 °C (50 °F) and crowd into the central area of the hive to form a "winter cluster". The worker bees huddle around the queen bee at the center of the cluster, shivering to keep the center between 27 °C (81 °F) at the start of winter (during the broodless period) and 34 °C (93 °F) once the queen resumes laying. The worker bees rotate through the cluster from the outside to the inside so that no bee gets too cold. The outside edges of the cluster stay at about 8–9 °C (46–48 °F). The colder the weather is outside, the more compact the cluster becomes. During winter, they consume their stored honey to produce body heat.
The amount of honey consumed during the winter is a function of winter length and severity, but ranges in temperate climates from 15 to 50 kg (30 to 100 pounds).^[10]

Foragers coming in loaded with pollen on the hive landing board

Pollination

Species of Apis are generalist floral visitors, and will pollinate a large variety of plants, but by no means all plants. Of all the honey bee species, only Apis mellifera has been used extensively for commercial pollination of crops and other plants. The value of these pollination services is commonly measured in the billions of dollars. Bees collect 66 pounds of pollen per year, per hive.^[11]

Honey bee pollinating flowers

A colony of Apis dorsata, the giant honey bee on their comb.

Play media

Pollinating flowers

Bee (Apis)

A forager collecting pollen

Bee products

Honey

Honey is the complex substance made when the nectar and sweet deposits from plants and trees are gathered, modified, and stored in the honeycomb by honey bees as a food source for the colony. All living species of Apis have had their honey gathered by indigenous peoples for consumption, though for commercial purposes, only A. mellifera and A. cerana have been utilized to any degree. Honey is sometimes also gathered by humans from the nests of various stingless bees.
In 1911, a bee culturist estimated a quart (about a litre) of honey represented bees flying over an estimated 48,000 miles to gather the nectar needed to produce the honey.^[12]

Nectar

Nectar, a liquid high in sucrose, is produced in plant glands known as nectaries. It is an important energy resource for honey bees and plays a significant role in foraging economics and evolutionary differentiation between different subspecies. It was proposed through an experiment conducted with the African honey bee, A. m. scutellata, that nectar temperature impacts the foraging decisions of honey bees.^[13]

Beeswax

Worker bees of a certain age will secrete beeswax from a series of glands on their abdomens. They use the wax to form the walls and caps of the comb. As with honey, beeswax is gathered by humans for various purposes.

Pollen

Bees collect pollen in the pollen basket and carry it back to the hive. In the hive, pollen is used as a protein source necessary during brood-rearing. In certain environments, excess pollen can be collected from the hives of A. mellifera and A. cerana. It is often eaten as a health supplement. It also has been used with moderate success as a source of pollen for hand pollination However, pollen collected by bees and harvested for pollination must be used within a few hours because it loses its potency rapidly, possibly because of the effects of enzymes or other chemicals from the bees; hand-collected pollen may remain usable for weeks, if stored promptly under suitable conditions.

Propolis

Propolis or bee glue is created from resins, balsams, and tree saps. Those species of honey bees that nest in tree cavities use propolis to seal cracks in the hive. Dwarf honey bees use propolis to defend against ants by coating the branch from which their nest is suspended to create a sticky moat.
Propolis is consumed by humans as a health supplement in various ways and also used in some cosmetics.

Sexes and castes

A caste is a different form, morphologically or reproductively, within the same sex of a species.
Honey bees have three castes, drones, workers, and queens. There are two sexes: drones are male, while workers and queens are female.

Drones

Males or drones are typically haploid, having only one set of chromosomes. They are produced by the queen if she chooses not to fertilize an egg; or by an unfertilized laying worker. Diploid drones may be produced if an egg is fertilized but is homozygous for the sex-determination allele. Drones take 24 days to develop and may be produced from summer through autumn. Drones have large eyes used to locate queens during mating flights. Drones do not have a sting.

Workers

Workers are female bees and have two sets of chromosomes. They are produced from an egg that the queen has selectively fertilized from stored sperm. Workers typically develop in 21 days. A typical colony may contain as many as 60,000 worker bees. Workers exhibit a wider range of behaviors than either queens or drones. Their duties change upon the age of the bee in the following order (beginning with cleaning out their own cell after eating through their capped brood cell): feed brood, receive nectar, clean hive, guard duty, and foraging. Some workers engage in other specialized behaviors, such as "undertaking" (removing corpses of their nestmates from inside the hive).

Workers have morphological specializations, including the corbiculum or pollen basket, abdominal glands that produce beeswax, brood-feeding glands, and barbs on the sting. Under certain conditions (for example, if the colony becomes queenless), a worker may develop ovaries.

Queens

Queen honey bees, like workers, are female. They are created at the decision of the worker bees by feeding a larva only royal jelly throughout its development, rather than switching from royal jelly to pollen once the larva grows past a certain size. Queens are produced in oversized cells and develop in only 16 days. Queens have a different morphology and behavior from worker bees. In addition to the greater size of the queen, she has a functional set of ovaries, and a spermatheca, which stores and maintains sperm after she has mated. The sting of queens is not barbed like a worker's sting, and queens lack the glands that produce beeswax. Once mated, queens may lay up to 2,000 eggs per day.
They produce a variety of pheromones that regulate behavior of workers, and helps swarms track the queen's location during the migratory phase.

Defense

Apis cerana japonica forming a ball around two hornets: The body heat trapped by the ball will overheat and kill the hornets.

All honey bees live in colonies where the workers sting intruders as a form of defense, and alarmed bees release a pheromone that stimulates the attack response in other bees. The different species of honey bees are distinguished from all other bee species (and virtually all other Hymenoptera) by the possession of small barbs on the sting, but these barbs are found only in the worker bees. The sting and associated venom sac of honey bees are also modified so as to pull free of the body once lodged (autotomy), and the sting apparatus has its own musculature and ganglion, which allow it to keep delivering venom once detached. The worker dies after the sting becomes lodged and is subsequently torn loose from the bee's abdomen. The honey bee's venom, known as apitoxin, carries several active components, the most abundant of which is melittin, and the most destructive Phospholipase A2.

This complex apparatus, including the barbs on the sting, is thought to have evolved specifically in response to predation by vertebrates, as the barbs do not usually function (and the sting apparatus does not detach) unless the sting is embedded in fleshy tissue. While the sting can also penetrate the membranes between joints in the exoskeleton of other insects (and is used in fights between queens), in the case of Apis cerana japonica, defense against larger insects such as predatory wasps (e.g. Asian giant hornet) is usually performed by surrounding the intruder with a mass of defending worker bees, which vibrate their muscles vigorously to raise the temperature of the intruder to a lethal level.^[14] Previously, heat alone was thought to be responsible for killing intruding wasps, but recent experiments have demonstrated the increased temperature in combination with increased carbon dioxide levels within the ball produce the lethal effect.^[15][16] This phenomenon is also used to kill a queen perceived as intruding or defective, an action known to beekeepers as 'balling the queen', named for the ball of bees formed.

In the case of those honey bee species with open combs (e.g., A. dorsata), would-be predators are given a warning signal that takes the form of a "Mexican wave" that spreads as a ripple across a layer of bees densely packed on the surface of the comb when a threat is perceived, and consists of bees momentarily arching their bodies and flicking their wings.^[17]

Communication

Honey bees are known to communicate through many different chemicals and odors, as is common in insects, but also using specific behaviours that convey information about the quality and type of resources in the environment, and where these resources are located. The details of the signalling being used vary from species to species; for example, the two smallest species, Apis andreniformis and A. florea, dance on the upper surface of the comb, which is horizontal (not vertical, as in other species), and worker bees orient the dance in the actual compass direction of the resource to which they are recruiting.
Apis mellifera carnica honey bees use their antennae asymmetrically for social interactions with a strong lateral preference to use their right antenna.^[18][19]

Symbolism

Both the Atharva Veda^[20] and the ancient Greeks associated lips anointed with honey with the gift of eloquence and even of prescience. The priestess at Delphi was the "Delphic Bee". The Quran has a chapter titled "The Bee".
A community of honey bees has often been employed throughout history by political theorists as a model of human society:

This image occurs in Aristotle and Plato; in Virgil^[21] and Seneca; in Erasmus and Shakespeare; in Marx and Tolstoy.^[22]

Honey bees, signifying immortality and resurrection, were royal emblems of the Merovingians, revived by Napoleon.^[23] The bee also is the heraldic emblem of the Barberini.

No Glass Ceiling for Worker Bees

By JAMES GORMAN

SEPT. 8, 2014

Original link:  http://www.nytimes.com/2014/09/09/science/no-glass-ceiling-for-worker-bees.html?_r=1 

The honeybee hive would not seem to be the place to look for individuality, flexibility in job duties and social mobility. But by using new techniques for analyzing bee behavior, researchers at the University of Illinois at Urbana-Champaign, recently found that the life of a bee is less rigidly determined than had been thought.

They first discovered that an elite 20 percent of foragers do 50 percent of all the foraging, and then found that membership in this group was surprisingly flexible. When the elite bees were removed from the hive, less hard-working bees raised the level of their activity and a new elite emerged.

Gene E. Robinson, the director of the Institute for Genomic Biology at the university, said he and other researchers set out to look at the behavior of bees in a new way partly because of “an increasing appreciation of the role of the individual in social insects.”

Teasing out the differences in individual levels of foraging activity required some new tools for observing the bees and for analyzing the data.

To work on the first part of the problem, Dr. Robinson said, Paul Tenczar, a retired computer entrepreneur and enthusiastic citizen scientist, joined the lab. He worked with scientists to devise a kind of E-ZPass system for bees involving tiny electronic ID tags, entry and exit tubes for a hive, and laser scanners to track the bees as they passed through the tubes (think toll plazas).

But even with the technology functioning at a high level to track the bees’ activity, analytical tools had to be developed to understand and interpret the data, Dr. Robinson said.

The results, which the team of scientists reported in the September issue of Animal Behaviour, showed first that there was an elite group among the foraging bees.

Then, by removing those top performers, the team found that other bees took their place. It was, said Dr. Robinson, “elitism with a populist streak.”

They also found, in mining the data, that over the life of an individual bee, patterns of foraging activity fluctuated and that individual bees had different life histories.

The approach to studying behavior using so-called big data is like that used by Internet companies to track people’s shopping behavior. Such new techniques, Dr. Robinson said, showed the power of “massive amounts of surveillance” to “reveal previously inaccessible data about individual behavior” in insects. And just when bees thought Facebook had ignored them.