A honey bee (or honeybee) is a eusocial, flying insect within the genus Apis of the bee clade. They are known for construction of perennial, colonial nests from wax, for the large size of their colonies, and for their surplus production and storage of honey, distinguishing their hives as a prized foraging target of many animals, including honey badgers, bears and human hunter-gatherers. In the early 21st century, only seven species of honey bee are recognized, with a total of 44 subspecies,[1] though historically seven to eleven species are recognized. The best known honey bee is the Western honey bee which has been domesticated for honey production and crop pollination; modern humans also value the wax for candlemaking and other crafts. Honey bees represent only a small fraction of the roughly 20,000 known species of bees.[2] Some other types of related bees produce and store honey and have been kept by humans for that purpose, including the stingless honey bees, but only members of the genus Apis are true honey bees. The study of bees, which includes the study of honey bees, is known as melittology.

Etymology and name

The genus name Apis is Latin for "bee".[3] Although modern dictionaries may refer to Apis as either honey bee or honeybee, entomologist Robert Snodgrass asserts that correct usage requires two words, i.e. honey bee, as it is a kind or type of bee, whereas it is incorrect to run the two words together, as in dragonfly or butterfly, because the latter are not flies.[4] Honey bee, not honeybee, is the listed common name in the Integrated Taxonomic Information System, the Entomological Society of America Common Names of Insects Database, and the Tree of Life Web Project.[5][6][7]

Origin, systematics and distribution

Distribution of honey bees around the world

Morphology of a female honey bee

Honey bees appear to have their center of origin in South and Southeast Asia (including the Philippines), as all the extant species except Apis mellifera 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.[8]

The first Apis bees appear in the fossil record at the Eocene-Oligocene boundary (34 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 the bees were present in Europe by that time. 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.[9]

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 species have been truly domesticated: Apis mellifera and Apis cerana indica. A. mellifera has been cultivated at least since the time of the building of the Egyptian pyramids, and only that species has been moved extensively beyond its native range.

Honey bees are the only extant members of the tribe Apini. Today's honey bees constitute three clades: Micrapis (dwarf honey bees), Megapis (giant honey bee), and Apis (domestic honey bees and close relatives).[1][10]

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.[10] Apis florea have smaller wing spans than its sister species.[11] Apis florea are also completely yellow with the exception of the scutellum of workers, which is black.[11]

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. A. d. binghami , the Indonesian giant 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. [12] A. d. laboriosa , the Himalayan giant 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 separate species. [10] 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.

, the giant honey bee, is native and widespread across most of South and Southeast Asia.

Apis

Eastern Apis species include three or four species, including A. koschevnikovi, Apis nigrocincta, and A. cerana. The genetics of the western honey bee A. mellifera are unclear.

Koschevnikov's honey bee

Koschevnikov's honey bee (Apis koschevnikovi) is often referred to in the literature as the “red bee of Sabah;” however, A. koschevnikovi is pale reddish in Sabah State, Borneo, Malaysia, but a dark, coppery color in the Malay Peninsula and Sumatra, Indonesia.[13] Its habitat is limited to the tropical evergreen forests of the Malay Peninsula, Borneo and Sumatra and they do not live in tropical evergreen rain forests which extend into Thailand, Myanmar, Cambodia and Vietnam.[13]

Philippine honey bee

Apis nigrocincta is a cavity-nesting species. The species has rust-colored scapes, legs, and cylpeuses, with reddish-tan hair color that covers most of the body.[14]

Eastern honey bee

Apis cerana, the eastern honey bee proper, is the traditional honey bee of southern and eastern Asia. It was domesticated as subspecies A. c. indica and kept in hives in a fashion similar to A. mellifera, though on a more limited, regional 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 separate species.[10]

Western honey bee

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

A. mellifera, the most common domesticated[15] species, was the third insect to have its genome mapped. It seems to have originated in eastern tropical Africa and spread from there to 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 breeds such as the Buckfast bee, have been bred. Behavior, color, and anatomy can be quite different from one subspecies or even strain to another.[citation needed]

A. mellifera phylogeny is the most enigmatic of all 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.[citation needed]

The diversity of A. mellifera 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.[10]

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. 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 to Utah in the late 1840s, and by ship to California in the early 1850s.[16]

An African bee 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 European bees and do not create as much of a honey surplus, 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.

Living and fossil honey bees (Apini: Apis)

Tribe Apini Latreille[17]

Genus Apis Linnaeus (s. lato)

henshawi species group († Priorapis Engel, † Synapis Cockerell) † A. vetusta Engel † A. henshawi Cockerell † A. petrefacta (Říha) † A. miocenica Hong † A. "longtibia" Zhang † A. "Miocene 1"

species group († Engel, † Cockerell) armbrusteri species group († Cascapis Engel) † A. armbrusteri Zeuner † A. nearctica , sp. Nov.

species group († Engel) florea species group ( Micrapis Ashmead) A. florea Fabricius A. andreniformis Smith

species group ( Ashmead) dorsata species group ( Megapis Ashmead) † A. lithohermaea Engel A. dorsata Fabricius

species group ( Ashmead) mellifera species group ( Apis Linnaeus s. stricto ) mellifera subgroup A. mellifera Linnaeus ( Apis Linnaeus s. strictissimo ) cerana subgroup ( Sigmatapis Maa) A. cerana Fabricius A. nigrocincta Smith A. koschevnikovi Enderlein

species group ( Linnaeus )

Life cycle

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;[18] and tens of thousands of sterile female worker bees. Details vary among the different species of honey bees, but common features include:

Eggs are laid singly in a cell in a wax honeycomb, produced and shaped by the worker bees. Using her spermatheca, the queen 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. Young worker bees, sometimes called "nurse 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. 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". Honey bees also perform tremble dances, which recruit receiver bees to collect nectar from returning foragers. 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. 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 which was scouted by worker bees beforehand and whose location is communicated with a special type of dance. Once the swarm arrives, 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".

Life cycle

Honey bee eggs shown in opened wax cells

Eggs and larvae

Drone pupae

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

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 kilograms (33 to 110 lb).[19] In addition, certain bees, including the Western honey bee as well as Apis cerana, are known to engage in effective methods of nest thermoregulation during periods of varying temperature in both summer and winter. During the summer, however, this is achieved through fanning and water evaporation from water collected in various fields.[20]

Pollination

Of all the honey bee species, only A. mellifera has been used extensively for commercial pollination of fruit and vegetable crops. The scale of these pollination services is commonly measured in the billions of dollars, credited with adding about 9% to the value of crops across the world. However, despite contributing substantially to crop pollination, there is debate about the potential spillover to natural landscapes and competition between managed honey bees and many of the ~20,000 species of wild pollinators.[21]

Species of Apis are generalist floral visitors, and pollinate many species of flowering plants, but because of their "generalized" nature, they do so inefficiently. Without specialized adaptations for specific flowers, their ability to reach pollen and nectar is often limited. What's more, their tendency to visit all species in a given area means that the pollen they carry for any one species is often very diluted. As such, they can provide some pollination to many plants, especially non-native crops, but most native plants have some native pollinator that is far more effective at pollinating that species.[22] When honeybees are present as an invasive species in an area, they compete for flowers with native pollinators, which can actually push out the native species.[23]

Claims of human dependency

European honey bees are often described as being essential to all human food production, leading to claims that without their pollination, all of humanity would starve, or even die out.[24][25] Einstein is sometimes misquoted as saying If bees disappeared off the face of the earth, man would only have four years left to live.[26] But not only did the scientist not say that, there is no science to support the prediction, itself.[27] In fact, many important crops need no insect pollination at all. The ten most important crops,[28] comprising 60% of all human food energy,[29] all fall into this category: Plantains are sterile and propagated by cuttings, as are cassava. Potatoes, yams, and sweet potatoes are root vegetables propagated by tubers. Soybeans are self-pollinated. Rice, wheat, and corn are all wind-pollinated, because this is true of all grasses.

Similarly, no crops originating in the New World depend on the domesticated honey bee Apis mellifera at all, as the insect is invasive, having been brought over with colonists in the last few centuries. Thomas Jefferson mentioned this in his Notes on the State of Virginia:

“ The honey-bee is not a native of our continent. Marcgrave indeed mentions a species of honey-bee in Brasil. But this has no sting, and is therefore different from the one we have, which resembles perfectly that of Europe. The Indians concur with us in the tradition that it was brought from Europe; but, when, and by whom, we know not. The bees have generally extended themselves into the country, a little in advance of the white settlers. The Indians therefore call them the white man's fly, and consider their approach as indicating the approach of the settlements of the whites.[30] ”

Tomatoes, peppers, squash, and all other New World crops evolved with native pollinators like squash bees, bumble bees, other native bees. The stingless bees mentioned by Jefferson are distant relatives of the honey bees, in the genus Melipona.

Nutrition

Honey bees obtain all of their nutritional requirements from a diverse combination of pollen and nectar. Pollen is the only natural protein source for honey bees. Adult worker honey bees consume 3.4–4.3 mg of pollen per day to meet a dry matter requirement of 66–74% protein.[31] The rearing of one larva requires 125-187.5 mg pollen or 25-37.5 mg protein for proper development.[31] Dietary proteins are broken down into amino acids, ten of which are considered essential to honey bees: methionine, tryptophan, arginine, lysine, histidine, phenylalanine, isoleucine, threonine, leucine, and valine. Of these amino acids, honey bees require highest concentrations of leucine, isoleucine, and valine, however elevated concentrations of arginine and lysine are required for brood rearing.[32] In addition to these amino acids, some B vitamins including biotin, folic acid, nicotinamide, riboflavin, thiamine, pantothenate, and most importantly, pyridoxine are required to rear larvae. Pyridoxine is the most prevalent B vitamin found in royal jelly and concentrations vary throughout the foraging season with lowest concentrations found in May and highest concentrations found in July and August. Honey bees lacking dietary pyridoxine were unable to rear brood.[32]

A forager collecting pollen

Pollen is also a lipid source for honey bees ranging from 0.8% to 18.9%.[31] Lipids are metabolized during the brood stage for precursors required for future biosynthesis. Fat-soluble vitamins A, D, E, and K are not considered essential but have shown to significantly improve the number of brood reared.[31] Honey bees ingest phytosterols from pollen to produce 24-methylenecholesterol and other sterols as they cannot directly synthesize cholesterol from phytosterols. Nurse bees have the ability to selectively transfer sterols to larvae through brood food.[31]

Nectar is collected by foraging worker bees as a source of water and carbohydrates in the form of sucrose. The dominant monosaccharides in honey bee diets are fructose and glucose but the most common circulating sugar in hemolymph is trehalose which is a disaccharide consisting of two glucose molecules.[33] Adult worker honey bees require 4 mg of utilizable sugars per day and larvae require about 59.4 mg of carbohydrates for proper development.[31]

Honey bees require water to maintain osmotic homeostasis, prepare liquid brood food, and to cool the hive through evaporation. A colony's water needs can generally be met by nectar foraging as it has high water content. Occasionally on hot days or when nectar is limited, foragers will collect water from streams or ponds to meet the needs of the hive.[34]

Parasites

Galleria mellonella

Larval stages of the G. mellonella moth parasitize both wild and cultivated honeybees. Eggs are laid within the hive, and the larva that hatch tunnel through and destroy the honeycombs that contain bee larva and their honey stores. The tunnels they create are lined with silk, which entangles and starves emerging bees. Destruction of honeycombs also result in honey leaking and being wasted. Both G. mellonella adults and larvae are possible vectors for pathogens that can infect bees, including the Israeli acute paralysis virus and the black queen cell virus.[35]

Management

Temperature treatments are possible, but also distorts wax of the honeycombs. Chemical fumigants, particularly CO 2 , are also used.[35]

Beekeeping

The only domesticated species of honey bee are A. mellifera and A. cerana, and they are often maintained, fed, and transported by beekeepers. In Japan, where mellifera is vulnerable to local hornets and disease, the Japanese honey bee a. cerana japonica is used in its place. 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. Bees of various types other than honey bees are also domesticated and used for pollination or other means around the world, including Tetragonula iridipennis in India, the blue orchard bee for tree nut and fruit pollination in the United States, and a number of species of Bombus (bumblebees) for pollination in various regions globally, such as tomatoes, which are not effectively pollinated by honey bees.[36]

Colony collapse disorder

Primarily in places where the bee was imported by humans, periodic collapses in honeybee populations have occurred at least since the late 19th century.[37] Starting in the first decade of the 21st century, abnormally high die-offs (30–70% of hives) of European honey bee colonies have occurred in North America. This has been dubbed "colony collapse disorder" (CCD) and was at first unexplained.[38] It seems to be caused by a combination of factors rather than a single pathogen or poison, possibly including neonicotinoid pesticides[39] or Israeli acute paralysis virus.[40]

Bee products

Honey

Honey is the complex substance made when bees ingest nectar, process it, and store the substance into honey combs.[41] All living species of Apis have had their honey gathered by indigenous peoples for consumption. A. mellifera and A. cerana are the only species that have had their honey harvested for commercial purposes.

Beeswax

Worker bees of a certain age secrete beeswax from a series of exocrine glands on their abdomens.[42] They use the wax to form the walls and caps of the comb. As with honey, beeswax is gathered by humans for various purposes such as candle making, waterproofing, soap and cosmetics manufacturing, pharmaceuticals, art, furniture polish and more.[43]

Bee bread

Bees collect pollen in their pollen baskets and carry it back to the hive.[44]

Worker bees combine pollen, honey and glandular secretions and allow it to ferment in the comb to make bee bread. The fermentation process releases additional nutrients from the pollen and can produce antibiotics and fatty acids which inhibit spoilage.[45] Bee bread is eaten by nurse bees (younger workers) which produce the protein-rich royal jelly needed by the queen and developing larvae in their hypopharyngeal glands. 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. The product is used as a health supplement. It has been used with moderate success as a source of pollen for hand pollination.

Bee brood

Bee brood – the eggs, larvae or pupae of honeybees – is nutritious and seen as a delicacy in countries such as Indonesia,[46] Mexico, Thailand, and many African countries; it has been consumed since ancient times by the Chinese and Egyptians.[a][48][49]

Propolis

Propolis is a resinous mixture collected by honey bees from tree buds, sap flows or other botanical sources, which is used as a sealant for unwanted open spaces in the hive.[50] Although propolis is alleged to have health benefits (tincture of Propolis is marketed as a cold and flu remedy), it may cause severe allergic reactions in some individuals.[51] Propolis is also used in wood finishes, and gives a Stradivarius violin its unique red color.[52]

Royal jelly

Royal jelly is a honey-bee secretion used to nourish the larvae.[53] It is marketed for its alleged but unsupported claims of health benefits.[54][55] On the other hand, it may cause severe allergic reactions in some individuals.[56]

Sexes and castes

Honey bees have three castes: drones, workers, and queens.[57][58] Drones are male, while workers and queens are female.[58]

Drones

Honey bees have a haplodiploid system of sex determination.

Males, or drones, are typically haploid, having only one set of chromosomes, and primarily exist for the purpose of reproduction.[58] They are produced by the queen if she chooses not to fertilize an egg or by an unfertilized laying worker. There are rare instances of diploid drone larvae. This phenomenon usually arises when there is more than two generations of brother-sister mating.[59] Sex determination in honey bees is initially due to a single locus, called the complementary sex determiner (csd) gene. In developing bees, if the conditions are that the individual is heterozygous for the csd gene, they will develop into females. If the conditions are so that the individual is hemizygous or homozygous for the csd gene, they will develop into males. The instances where the individual is homozygous at this gene are the instances of diploid males.[60] Drones take 24 days to develop, and may be produced from summer through to autumn, numbering as many as 500 per hive.[58] They are expelled from the hive during the winter months when the hive's primary focus is warmth and food conservation.[58] Drones have large eyes used to locate queens during mating flights. They do not defend the hive or kill intruders, and do not have a stinger.[61]

Workers

Workers have two sets of chromosomes.[62] 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.[58] 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.[58][61] Some workers engage in other specialized behaviors, such as "undertaking" (removing corpses of their nestmates from inside the hive).[61]

Workers have morphological specializations, including the pollen basket (corbicula),[63] 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.

Worker honey bees perform different behavioural tasks that cause them to be exposed to different local environments.[64][65] The gut microbial composition of workers varies according to the landscape and plant species they forage, such as differences in rapeseed crops,[64] and with different hive tasks, such as nursing or food processing.[65]

Queens

Queen honey bees are created when worker bees feed a single female larvae an exclusive diet of a food called "royal jelly".[58][61] Queens are produced in oversized cells and develop in only 16 days; they differ in physiology, 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. Apis queens practice polyandry, with one female mating with multiple males. The highest documented mating frequency for an Apis queen is in Apis nigrocincta, where queens mate with an extremely high number of males with observed numbers of different matings ranging from 42 to 69 drones per queen.[66] 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.[61] They produce a variety of pheromones that regulate behavior of workers, and helps swarms track the queen's location during the swarming.[61]

Queen-worker conflict

When a fertile female worker produces drones, a conflict arises between her interests and those of the queen. The worker shares half her genes with the drone and one-quarter with her brothers, favouring her offspring over those of the queen. The queen shares half her genes with her sons and one-quarter with the sons of fertile female workers.[67] This pits the worker against the queen and other workers, who try to maximize their reproductive fitness by rearing the offspring most related to them. This relationship leads to a phenomenon known as "worker policing". In these rare situations, other worker bees in the hive who are genetically more related to the queen's sons than those of the fertile workers will patrol the hive and remove worker-laid eggs. Another form of worker-based policing is aggression toward fertile females.[68] Some studies have suggested a queen pheromone which may help workers distinguish worker- and queen-laid eggs, but others indicate egg viability as the key factor in eliciting the behavior.[69][70] Worker policing is an example of forced altruism, where the benefits of worker reproduction are minimized and that of rearing the queen's offspring maximized.

In very rare instances workers subvert the policing mechanisms of the hive, laying eggs which are removed at a lower rate by other workers; this is known as anarchic syndrome. Anarchic workers can activate their ovaries at a higher rate and contribute a greater proportion of males to the hive. Although an increase in the number of drones would decrease the overall productivity of the hive, the reproductive fitness of the drones' mother would increase. Anarchic syndrome is an example of selection working in opposite directions at the individual and group levels for the stability of the hive.[71]

Under ordinary circumstances the death (or removal) of a queen increases reproduction in workers, and a significant proportion of workers will have active ovaries in the absence of a queen. The workers of the hive produce a last batch of drones before the hive eventually collapses. Although during this period worker policing is usually absent, in certain groups of bees it continues.[72]

According to the strategy of kin selection, worker policing is not favored if a queen does not mate multiple times. Workers would be related by three-quarters of their genes, and the difference in relationship between sons of the queen and those of the other workers would decrease. The benefit of policing is negated, and policing is less favored. Experiments confirming this hypothesis have shown a correlation between higher mating rates and increased rates of worker policing in many species of social hymenoptera.[73]

Defense

Apis cerana japonica forming a ball around two 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 apparatus, including the barbs, may 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 ("balling").[74] 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.[75][76] 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.

Defense can vary based on the habitat of the bee. 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.[77] In cavity dwelling species such as Apis cerana, Apis mellifera, and Apis nigrocincta, entrances to these cavities are guarded and checked for intruders in incoming traffic. Another act of defense against nest invaders, particularly wasps, is "body shaking," a violent and pendulum like swaying of the abdomen, performed by worker bees.[78]

Venom

The sting and associated venom sac are modified so as to pull free of the body once lodged (autotomy), and the sting apparatus has its own musculature and ganglion that allow it to keep delivering venom once detached.[citation needed] The gland which produces the alarm pheromone is also associated with the sting apparatus. The embedded stinger continues to emit additional alarm pheromone after it has torn loose; other defensive workers are thereby attracted to the sting site. 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,[79] and the most biologically active are enzymes, particularly phospholipase A2.[80]

Bee venom is under laboratory and clinical research for its potential properties and uses in reducing risks for adverse events from bee venom therapy,[81] rheumatoid arthritis,[82] and use as an immunotherapy for protection against allergies from insect stings.[83] Bee venom products are marketed in many countries, but, as of 2018, there are no approved clinical uses for these products which carry various warnings for potential allergic reactions.[84]

Competition

With an increased number of honey bees in a specific area due to beekeeping, domesticated bees and native wild bees often have to compete for the limited habitat and food sources available.[85] European bees may become defensive in response to the seasonal arrival of competition from other colonies, particularly Africanized bees which may be on the offence and defense year round due to their tropical origin.[86] In the United Kingdom, honey bees are known to compete with Bombus hortorum, a bumblebee species, because they forage at the same sites. To resolve the issue and maximize both their total consumption during foraging, bumblebees forage early in the morning, while honey bees forage during the afternoon.[87]

Communication

Honey bees are known to communicate through many different chemicals and odors, as is common in insects. They also rely on a sophisticated dance language that conveys information about the distance and direction to a specific location (typically a nutritional source, e.g., flowers or water). The dance language is also used during the process of reproductive fission, or swarming, when scouts communicate the location and quality of nesting sites.[88]

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 antennae.[89][90]

There has been speculation as to honeybee consciousness.[91]

Symbolism

The bee was used as a symbol of government by Emperor Napoleon I of France.[92] Both the Hindu Atharva Veda[93] 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". In ancient Egyptian mythology, honeybees were believed to be born from the tears of the Sun God, Ra.[94]

A community of honey bees has often been employed by political theorists as a model of human society, from Aristotle and Plato to Virgil.[95][96] Honey bees, signifying immortality and resurrection, were royal emblems of the Merovingians. The state of Utah is called the "Beehive State", the state emblem is the beehive, the state insect is the honey bee, and a beehive and the word "industry" appear on both the state flag and seal.[97]

Gallery

See also

Notes

^ Melipona beecheii, not from Apis honeybees.[47] The Mayans kept and collected honey and brood, but from stingless social bees such as, not fromhoneybees.