Africanized honey bees, known colloquially as "killer bees", are some hybrid varieties of the Western honey bee species, (Apis mellifera), produced originally by cross-breeding of the African honey bee A. m. scutellata, with various European honey bees such as the Italian bee A. m. ligustica and the Iberian bee A. m. iberiensis. The hybrid bees are far more defensive than any of the various European subspecies. Small swarms of Africanized bees are capable of taking over European honey bee hives by invading the hive and establishing their own queen after killing the European queen.^[1]

History[edit]

Western honey bees differentiated into geographic races as they spread from Africa into Eurasia. Migrating bee populations formed the original colonies of bee in western Europe, landing to eventually populate the continent from Africa across the Straits of Gibraltar.^[2] There are currently 28 recognized subspecies of Apis mellifera based largely on these geographic variations. All subspecies are cross fertile. Geographic isolation led to numerous local adaptations. These adaptations include brood cycles synchronized with the bloom period of local flora, forming a winter cluster in colder climates, migratory swarming in Africa, enhanced foraging behavior in desert areas, and numerous other inherited traits.

The Africanized honey bees in the Western Hemisphere are of mixed descent from 26 Tanganyikan queen bees of A. m. scutellata, accidentally released by a replacement bee-keeper in 1957 near Rio Claro, São Paulo, in the southeast of Brazil, from hives operated by biologist Warwick E. Kerr, who had interbred honey bees from Europe and southern Africa. Hives containing these particular queens were noted to be especially defensive. Kerr was attempting to breed a strain of bees that would produce more honey and be better adapted to tropical conditions (i.e., more productive) than the European subspecies of honey bee used in South America and southern North America. The hives the bees were released from had special excluder grates to prevent the larger queen bees and drones from getting out and mating with local queens and drones of European descent. However, following the accidental release, the African queens and drones mated with domesticated local non-African queens and drones, and their descendants have since spread throughout the Americas.

The Africanized bees have become the dominant type of honey bee for beekeeping in Central America and in tropical areas of South America due to them out competing the European sub species, and there are claims that they have improved productivity. Unfortunately, the extreme tendency of Africanized bees to swarm has had a significant impact of honey production in managed colonies and in most areas the Africanized bees tend to have certain behavioral traits that make them less desirable for managed beekeeping. Specifically, as compared with the European bee types, the Africanized bee:

• Tends to swarm more frequently and go farther than other types of honey bees.
• Is more likely to migrate as part of a seasonal response to lowered food supply.
• Is more likely to "abscond"—the entire colony leaves the hive and relocates—in response to stress.
• Has greater defensiveness when in a resting swarm, compared to other honey bee types.
• Lives more often in ground cavities than the European types.
• Guards the hive aggressively, with a larger alarm zone around the hive.
• Has a higher proportion of "guard" bees within the hive.
• Deploys in greater numbers for defense and pursues perceived threats over much longer distances from the hive.
• Cannot survive extended periods of forage deprivation, preventing introduction into areas with harsh winters or extremely dry late summers.

Geographic spread[edit]

Map showing the spread of Africanized honey bees in the United States from 1990 to 2003

As of 2002, the Africanized honeybees had spread from Brazil south to northern Argentina and north to Central America, Trinidad (West Indies), Mexico, Texas, Arizona, Nevada, New Mexico, Florida, and southern California. Their expansion stopped for a time at eastern Texas, possibly due to the large population of honey bee hives in the area. However, discoveries of the Africanized bees in southern Louisiana indicate this subspecies has penetrated this barrier,^[3] or has come as a swarm aboard a ship. In June 2005, it was discovered that the bees had penetrated the border of Texas and had spread into southwest Arkansas. On September 11, 2007, Commissioner Bob Odom of the Department of Agriculture and Forestry said that Africanized honey bees established themselves in the New Orleans area.^[4] In February 2009, Africanized honeybees were found in southern Utah.^[5][6] In October 2010, a 73-year-old man was killed by a swarm of Africanized honey bees while clearing brush on his south Georgia property, as determined by Georgia's Department of Agriculture. In 2012 state officials reported that a colony was found for the first time in a bee keepers colony in Monroe County, eastern Tennessee.^[7] In June 2013 62-year old Larry Goodwin, of Moody, Texas, was killed by a swarm of bees.^[8]

In tropical climates they compete effectively against European bees and, at their peak rate of expansion, they spread north at a rate of almost two kilometers (about one mile) a day. There were discussions about slowing the spread by placing large numbers of docile European-strain hives in strategic locations, particularly at the Isthmus of Panama, but various national and international agricultural departments were unable to prevent the bees' expansion. Current knowledge of the genetics of these bees suggests that such a strategy, had it been attempted, would not have been successful.^[9]

As the Africanized honeybee migrates further north, colonies are interbreeding with European honeybees. There are now relatively stable geographic zones in which either African bees dominate, a mix of African and European bees is present, or only non-African bees are found, as in southern South America or northern North America.

African honeybees abscond, abandon the hive and any food store to start over in a new location, more readily than European honeybees. This is not necessarily a severe loss in tropical climates where plants bloom all year but in more temperate climates it can leave the colony with insufficient stores to survive the winter. Thus Africanized bees are expected to be a hazard mostly in the Southern States of the United States, reaching as far north as the Chesapeake Bay in the east. The cold-weather limits of the African bee have driven some professional bee breeders from Southern California into the harsher wintering locales of the northern Sierra Nevada and southern Cascade Range. This is a more difficult area to prepare bees for early pollination placement in, such as is required for the production of almonds. The reduced available winter forage in northern California means that bees must be fed for early spring buildup.

The arrival of honeybees in Central America is a threat to the ancient art of keeping stingless bees in log gums even though they do not interbreed or directly compete with the stingless bees. The honey productivity of the honey bees exceeds the productivity of the native stingless bees so much that economic pressures force beekeepers to switch.

African honeybees are considered an invasive species in many regions.

Morphology and genetics[edit]

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

The popular term 'Killer bee' has only limited scientific meaning today because there is no generally accepted fraction of genetic contribution used to establish a cut-off. While the native African scutellata are smaller, and build smaller comb cells than the European bees, their hybrids are not smaller. Africanized bees have slightly shorter wings, which can only be recognized reliably by performing a statistical analysis on micro-measurements of a substantial sample. One problem with this test is that there are also other subspecies, such as Apis mellifera iberiensis, which have shorter wings. This trait is thought to derive from ancient hybrid haplotypes thought to have links to evolutionary lineages from Africa. Some belong to Apis mellifera intermissa but others have an indeterminate origin; the Egyptian honeybee (Apis mellifera lamarckii), present in small numbers in the southeastern United States, has the same morphology. Currently testing techniques have moved away from external measurements to DNA analysis, but this means the test can only be done by a sophisticated laboratory. Molecular diagnostics using the mitochondrial DNA (mtDNA) cytochrome b gene can differentiate A. m. scutellata from other A. mellifera lineages, though mtDNA only allows one to detect an Africanized colony that has an Africanized queen, and not colonies where a European queen has mated with Africanized drones.^[10]

The Western honey bee is native to the continents of Europe, Asia, and Africa. As of the early 1600s, the insect was introduced to North America, with subsequent introductions of other European subspecies two centuries later.^[11] Since then, they have spread throughout the Americas. The 28 subspecies can be assigned to one of four major branches based on work by Ruttner and subsequently confirmed by analysis of mitochondrial DNA. African subspecies are assigned to branch A, northwest European subspecies to branch M, southwest European subspecies to branch C, and Mideast subspecies to branch O. The subspecies are grouped and listed. There are still regions with localized variations that may become identified subspecies in the near future, such as A. m. pomonella from the Tian Shan mountains, which would be included in the Mideast subspecies branch.

The Western honey bee is the third insect to have its genome mapped, and is unusual in having very few transposons. According to the scientists who analysed its genetic code, the western honey bee originated in Africa and spread to Eurasia in two ancient migrations.^[12] They have also discovered that the number of genes in the honey bees related to smell outnumber those for taste.^[13] The genome sequence revealed several groups of genes, particularly the genes related to circadian rhythms, were closer to vertebrates than other insects. Genes related to enzymes that control other genes were also vertebrate-like.^[14]

Besides, A. m. iberica haplotype is present in the honey bees of the western United States,^[15] Mexico and South America, where the honey bees are not native and they were introduced from Spain during the conquest of America, from populations with African haplotypes, whose origin is indeterminate. Apis mellifera iberica is having hybridization between the north of African and European bees, Apis mellifera mellifera, and Apis mellifera intermissa.^[16] Presents six haplotypes different, five of them correspond to an evolutionary lineage from Africa and one from Western Europe. From this, infer the hybrid nature of this subspecies, is similar to that of African populations in the number of alleles detected and the values of genetic diversity. Additionally A.m.intermissa genoma, present in A.m.iberica belongs to a group shown by experiment to have similar mtDNA, this including A. m. monticola, A. m. scutellata, A. m. adansonii and A. m. capensis .^[17][18][19]

Several researchers and beekeepers describe a general trait of the African subspecies Apis mellifera scutellata, classified by Lepeletier, 1836 - (African honey bee) Central and West Africa, which is absconding, where the Africanized honeybee colonies abscond the hive in times when food-stores are low, unlike the European colonies which tend to die in the hive.

There are two lineages of African subspecies Apis mellifera scutellata in the Americas: actual matrilinial descendants of the original escaped queens and a much smaller number that are African through hybridization. The matrilinial descendants carry African mtDNA, but partially European nuclear DNA, while the bees that are African through hybridization carry European mtDNA, and partially African nuclear DNA. The matrilinial descendants are in the vast majority. This is supported by DNA analyses performed on the bees as they spread northwards; those that were at the "vanguard" were over 90% African mtDNA, indicating an unbroken matriline (Smith et al., 1989), but after several years in residence in an area interbreeding with the local European strains, as in Brazil, the overall representation of African mtDNA drops to some degree. However, these latter hybrid lines (with European mtDNA) do not appear to propagate themselves well or persist.^[20] Population genetics analysis of Africanized honey bees in the United States, using a materially inherited genetic marker, found 12 distinct mitotypes, and the amount of genetic variation observed supports the idea that there have been multiple introductions of AHB into the United States.^[21]

Consequences of selection[edit]

The chief difference between the European races or subspecies of bees kept by beekeepers and the African stock is attributable to selective breeding. The Africanized honey bee varieties produced a reversion of behaviour similar to non-domesticated species. The most common race used in the United States today is the Italian bee, Apis mellifera ligustica, which has been used for several thousand years in some parts of the world and in the Americas since the arrival of the European colonists. Beekeepers have tended to eliminate the fierce strains, and the entire race of bees has thus been gentled by selective breeding, from bee species naturally selected by the environment.

In central and southern Africa, the bees had to adapt to the environment of sub-saharan Africa—surviving prolonged droughts and having to defend themselves against other aggressive insects, as well as animals like the honey badger, that also will destroy hives if the bees are not sufficiently defensive. In addition, there was formerly no tradition of beekeeping, only bee robbing.

Defensiveness[edit]

African bees are characterized by greater defensiveness in established hives than European honey bees. They are more likely to attack a perceived threat and, when they do so, attack relentlessly in larger numbers. Also, they have been known to pursue their threat for over a mile. This aggressively protective behavior has been termed by scientists as hyper-defensive behavior. This defensiveness has earned them the nickname "killer bees", the aptness of which is debated. Over the decades, several deaths in the Americas have been attributed to African bees. The venom of an African bee is no more potent than that of a European honey bee, but since the former tends to sting in greater numbers, the number of deaths from them are greater than from the European honey bee.^{[citation needed]} However, allergic reaction to bee venom from any bee can kill a person, and it is difficult to estimate how many more people have died due to the presence of African bees.

Most human incidents with African bees occur within two or three years of the bees' arrival and then subside. Beekeepers can greatly reduce this problem by killing the queens of aggressive strains to breed gentler stock. Beekeepers in South Africa keep A. m. scutellata using common beekeeping practices without excessive problems.

Fear factor[edit]

The African bee is widely feared by the public, a reaction that has been amplified by sensationalist movies (such as The Swarm) and some of the media reports. Stings from African bees kill one or two people per year in the United States.^[22]

As the bee spreads through Florida, a densely populated state, officials worry that public fear may force misguided efforts to combat them.

rghsreater distances. An Africanized bee colony can remain agitated longer and may attack up to a quarter of a mile away from the hive.^{[citation needed]}

Queen management in African bee areas[edit]

In Mexico, where African bees are well established, pollination beekeepers have found that a purchased and pre-bred non-African queen may be used to locally create a first generation of virgin queens that are then bred in an uncontrolled fashion with the local wild African drones. These first generation African queens produce worker bees that are manageable, not exhibiting the intense and massive defense reactions of subsequent generations.

Impact on existing apiculture[edit]

In areas of suitable temperate climate, the survival traits of African queens and colonies outperform western honey bee colonies. This competitive edge leads to the dominance of African traits. In Brazil, the African hybrids are known as Assassin Bees, for their habit of taking over an existing hive of European bees; this habit is most evident when the hive being attacked has a weakened queen, so not all hives are equally vulnerable, and overall rates of hive usurpation can reach 20%.^[1]

Gentle African bees[edit]

Not all African hives show overly defensive behavior; some colonies are quiet, which gives a beginning point for beekeepers to breed a gentler stock.^[24] This has been done in Brazil, where bee incidents are much less common than they were during the first wave of the African bees' colonization. Now that the African bee has been "re-domesticated", it is considered the bee of choice for beekeeping in Brazil.^{[citation needed]}

References[edit]

Further reading[edit]

• Collet T., Ferreira K.M., Arias M.C., Soares A.E.E., Del Lama M.A. (2006). "Genetic structure of African honeybee populations (Apis mellifera L.) from Brazil and Uruguay viewed through mitochondrial DNA COI–COII patterns". Heredity 97: 329–335. doi:10.1038/sj.hdy.6800875. 
• Smith D.R., Taylor O.R., Brown W.M. (1989). "Neotropical African honey bees have African mitochondrial DNA". Nature 339: 213–215. 

The western honey bee or European honey bee (Apis mellifera) is a species of honey bee. The genus Apis is Latin for "bee", and mellifera comes from Latin melli- "honey" and ferre "to bear"—hence the scientific name means "honey-bearing bee". The name was coined in 1758 by Carolus Linnaeus who, upon realizing the bees do not bear honey, but nectar, tried later to correct it to Apis mellifica ("honey-making bee") in a subsequent publication. However, according to the rules of synonymy in zoological nomenclature, the older name has precedence. As of October 28, 2006, the Honey Bee Genome Sequencing Consortium fully sequenced and analyzed the genome of Apis mellifera.

In 2007, media attention focused on colony collapse disorder, a decline in European honey bee colonies in various parts of the world.

Geographic distribution[edit]

The western honey bee is native to the continents of Europe, Asia, and Africa. As of the early 1600s, the insect was introduced to North America, with subsequent introductions of other European subspecies two centuries later.^[1] Since then, they have spread throughout the Americas.

Western honey bees differentiated into geographic races as they spread from Africa into Eurasia.^[2] Currently, 28 subspecies based on these geographic variations are recognized.^{[citation needed]} All races are cross-fertile, though reproductive adaptations may make crossing unlikely. The 28 subspecies can be assigned to one of four major branches based on work by Ruttner, and subsequently confirmed by analysis of mitochondrial DNA. African subspecies are assigned to branch A, northwest European subspecies to branch M, southwest European subspecies to branch C, and Mideast subspecies to branch O. The subspecies are grouped and listed in the sidebar. Regions with localized variations may become identified subspecies in the near future, such as A. m. pomonella from the Tian Shan Mountains, which would be included in the Mideast subspecies branch.

Geographic isolation led to numerous adaptations as honey bees spread after the last ice age. These adaptations include brood cycles synchronized with the bloom period of local flora, forming a winter cluster in colder climates, migratory swarming in Africa, enhanced foraging behavior in desert areas, and numerous other inherited traits.

Biology, life cycle[edit]

Larvae to the left and eggs to the right

Pupae of drones

Stages of development of the drone pupae

In the temperate zone, honey bees survive winter as a colony, and the queen begins egg laying in mid to late winter, to prepare for spring. This is most likely triggered by longer day length. She is the only fertile female, and deposits all the eggs from which the other bees are produced. Except for a brief mating period when she may make several flights to mate with drones, or if she leaves in later life with a swarm to establish a new colony, the queen rarely leaves the hive after the larvae have become full-grown bees. The queen deposits each egg in a cell prepared by the worker bees. The egg hatches into a small larva which is fed by 'nurse' bees (worker bees which maintain the interior of the colony). After about a week, the larva is sealed up in its cell by the nurse bees and begins the pupal stage. After another week, it will emerge an adult bee.

For the first 10 days of their lives, the female worker bees clean the hive and feed the larvae. After this, they begin building comb cells. On days 16 through 20, a worker receives nectar and pollen from older workers and stores it. After the 20th day, a worker leaves the hive and spends the remainder of its life as a forager. The population of a healthy hive in mid-summer can average between 40,000 and 80,000 bees.

The larvae and pupae in a frame of honeycomb are referred to as frames of brood and are often sold (with adhering bees) by beekeepers to other beekeepers to start new beehives.

Both workers and queens are fed "royal jelly" during the first three days of the larval stage. Then workers are switched to a diet of pollen and nectar or diluted honey, while those intended for queens will continue to receive royal jelly. This causes the larva to develop to the pupa stage more quickly, while being also larger and fully developed sexually. Queen breeders consider good nutrition during the larval stage to be of critical importance to the quality of the queens raised, with good genetics and sufficient number of matings also being factors. During the larval and pupal stages, various parasites can attack the pupa/larva and destroy or damage it.

Queens are not raised in the typical horizontal brood cells of the honeycomb. The typical queen cell is specially constructed to be much larger, and has a vertical orientation. However, should the workers sense the old queen is weakening, they will produce emergency cells known as supersedure cells. These cells are made from a cell with an egg or very young larva. These cells protrude from the comb. As the queen finishes her larval feeding, and pupates, she moves into a head downward position, from which she will later chew her way out of the cell. At pupation, the workers cap or seal the cell. Just prior to emerging from their cells, young queens can often be heard "piping". The queen makes this noise to prove her space. If successful, this piping seems to have a calming and harmonizing effect on the worker bees.^[3]

Worker bees are infertile females, but in some circumstances, generally only in times of severe stress or with the loss or injury or declining health of the queen, they may lay infertile eggs, and in some subspecies these eggs may actually be fertile. However, since the worker bees are 'imperfect' females (not fully sexually developed), they do not mate with drones. Any fertile eggs they lay would be haploid, having only the genetic contribution of their mother, and in honey bees these haploid eggs will always develop into drones. Worker bees also secrete the wax used to build the hive, clean and maintain the hive, raise the young, guard the hive and forage for nectar and pollen.

In honey bees, the worker bees have a modified ovipositor called a stinger with which they can sting to defend the hive, but unlike other bees of any other genus (and even unlike the queens of their own species), the stinger is barbed. Contrary to popular belief, the bee will not always die soon after stinging: this misconception is based on the fact that a bee will usually die after stinging a human or other mammal. 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 which allow it to keep delivering venom once detached. This complex apparatus, including the barbs on the sting, is presumed to have evolved specifically in response to predation by vertebrates, as the barbs do not function (and the sting apparatus does not detach) unless the sting is embedded in elastic material. Even then, the barbs do not always "catch", so a bee may occasionally pull the sting free and either fly off unharmed, or sting again.

Drones[edit]

Drones are the male bees of the colony. Since they do not have ovipositors, they also do not have stingers. Drone honey bees do not forage for nectar or pollen. In some species, they are suspected of playing a contributing role in the temperature regulation of the hive. The primary purpose of a drone bee is to fertilize a new queen. Multiple drones will mate with any given queen in flight, and each will die immediately after mating; the process of insemination requires a lethally convulsive effort. Drone honey bees are haploid (having single, unpaired chromosomes) in their genetic structure and are descended only from their mother, the queen. They truly do not have a father. In essence, drones are the equivalent of flying gametes. In regions of temperate climate, the drones are generally expelled from the hive before winter and left to die of cold and starvation, since they are unable to forage, produce honey, or take care of themselves.

Life expectancy[edit]

The average lifespan of the queen in most subspecies is three to four years. However, reports from the German/European black bee subspecies previously used for beekeeping, indicate the queen could live up to eight years.^[4] Because queens deplete their store of sperm, towards the end of their lives, they start laying more and more unfertilized eggs. Beekeepers therefore frequently change queens every year or every other year.

The lifespan of the workers varies drastically over the year in places with an extended winter. Workers born in the spring and summer will work hard and live only a few weeks, whereas those born in the autumn will stay inside for several months as the colony clusters. On average during the year, about one percent of a colony's worker bees die naturally per day.^[5] Except for the queen, all of the colony's workers are therefore exchanged about every four months.

Honey production[edit]

Honey bee with tongue partially extended

Enlarged image of a Honey bee's "tongue".

Bees produce honey by collecting nectar, which is a clear liquid consisting of nearly 80% water, with complex sugars. The collecting bees store the nectar in a second stomach and return to the hive, where worker bees remove the nectar. The worker bees digest the raw nectar for about 30 minutes using enzymes to break up the complex sugars into simpler ones. Raw honey is then spread out in empty honeycomb cells to dry, which reduces the water content to less than 20%. When nectar is being processed, honey bees create a draft through the hive by fanning with their wings. Once dried, the cells of the honeycomb are sealed (capped) with wax to preserve the honey.

When a hive detects smoke, many bees become remarkably nonaggressive; this is speculated to be a defense mechanism. Wild colonies generally live in hollow trees, and when bees detect smoke, they are assumed to prepare to evacuate from a forest fire, carrying as much food reserve as they can. To do this, they will go to the nearest honey storage cells and gorge on honey. In this state, they are quite docile, since defense from predation is less important than saving as much food as possible.

Thermoregulation[edit]

The honey bee needs an internal body temperature of 35 °C (95 °F) to fly — which is also the temperature maintained within the cluster. The same temperature is required in the brood nest over a long period to develop the brood, and it is the optimal temperature for the creation of wax. The temperature on the periphery of the cluster varies with the outside air temperature and in the winter cluster, the internal temperature may be as low as 20–22 °C (68–72 °F).

Honey bees are able to forage over a 30 °C (54 °F) range of air temperature, largely because they have behavioural and physiological mechanisms for regulating the temperature of their flight muscles. From very low to very high air temperatures, the successive mechanisms are: shivering before flight and stopping flight for additional shivering, passive body temperature regulation in a comfort range that is a function of work effort, and finally, active heat dissipation by evaporative cooling from regurgitated honey sac contents. The body temperatures maintained differ depending on caste and expected foraging rewards.^[6]

The optimal air temperature for foraging is 22–25 °C (72–77 °F). During flight, the rather large flight muscles create heat, which must dissipate. The honey bee uses a form of evaporative cooling to release heat through its mouth. Under hot conditions, heat from the thorax is dissipated through the head; the bee regurgitates a droplet of hot internal fluid — a "honeycrop droplet" – which immediately cools the head temperature by 10 °C (18 °F).^[7]

Below 7–10 °C (45–50 °F), bees become immobile, and above 38 °C (100 °F), their activity slows. Honey bees can tolerate temperatures up to 50 °C (122 °F) for short periods.

Queens[edit]

Periodically, the colony determines a new queen is needed. There are three general triggers:

1. The colony becomes space-constrained because the hive is filled with honey, leaving little room for new eggs. This will trigger a swarm where the old queen will take about half the worker bees to found a new colony, leaving the new queen with the other half of worker bees to continue the old colony.
2. The old queen begins to fail. This is thought to be recognized by a decrease in queen pheromones throughout the hive. This situation is called supersedure; at the end of the supersedure, the old queen is generally killed.
3. The old queen dies suddenly. This situation is known as emergency supersedure. The worker bees will find several eggs or larvae of the right age-range, and attempt to develop them into queens. Emergency supersedure can generally be recognized because the new queen cells are built out from regular cells of the comb rather than hanging from the bottom of a frame.

Regardless of the trigger, the workers develop the larvae into queens by continuing to feed them royal jelly, which triggers an extended development as a pupa.

When the virgin queen emerges, she is commonly thought to seek out other queen cells and sting the infant queens within. Should two queens emerge simultaneously, they are thought to fight to the death. Recent studies, however, have indicated as many as 10% of Apis mellifera colonies may maintain two queens. The mechanism by which this occurs is not yet known, but it has been reported to occur more frequently in some South African subspecies.^{[citation needed]} Regardless, the queen asserts her control over the worker bees through the release of a complex suite of pheromones called queen scent.

Peanut-like queen brood cells are extended outward from the brood comb.

After several days of orientation within and around the hive, the young queen flies to a drone congregation point (a site near a clearing and generally about 30 feet (9.1 m) above the ground), where the drones from different hives tend to congregate in a swirling aerial mass. Drones detect the presence of a queen in their congregation area by her smell, and then find her by sight and mate with her in midair (drones can be induced to mate with "dummy" queens if they have the queen pheromone applied). A queen will mate multiple times and may leave to mate several days in a row, weather permitting, until her spermatheca is full.

The queen lays all the eggs in a healthy colony. The number and pace of egg-laying is controlled by weather, availability of resources and the characteristics of the specific race of honey bee. Queens generally begin to slow egg-laying in the early fall and may even stop during the winter. Egg-laying will generally resume in late winter as soon as the days begin to get longer and peak in the spring. At the height of the season, the queen may lay over 2500 eggs per day – more than her own body mass.

The queen fertilizes each egg as it is being laid into a worker-sized cell using stored sperm from the spermatheca. Eggs laid into drone-sized (larger) cells are left unfertilized. The unfertilized eggs have only half as many genes as the queen or worker eggs and develop into drones.

Queen-Worker Conflict[edit]

In instances where a fertile female worker produces drones, a conflict arises between her interests and those of the queen. The worker shares half of her genes with the drone and a quarter with her brothers, favoring her own offspring over those of the queen. The queen, however, shares half of her genes with her sons and only a quarter with the sons of fertile female workers.^[8] This situation pits the interest of the worker against those of the queen and other workers, who will each try to maximize their reproductive fitness by rearing the offspring most related to them. This relationship leads to the phenomenon known as "worker policing". In these rare situations, other worker bees in the hive which are more genetically related to the queen's sons than those of the fertile workers and will actively patrol the hive and remove the worker-laid eggs. Another form of worker-based policing is aggression toward the fertile females.^[9] Some studies have suggested the presence of a queen pheromone that may aid workers in discrimination of worker and queen-laid eggs, whereas other studies claim that egg viability is the key difference in eliciting the behavior.^[10][11] Worker policing is an example of forced altruism, in which the benefits of worker reproduction are reduced and the benefit of rearing the queen's offspring are raised.

In very rare instances, workers can subvert the policing mechanisms of the hive and lay eggs that are removed at a lower rate by other workers, a condition termed the "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 mother of the drones would greatly increase. Thus, the anarchic syndrome is an example of selection working at both the individual and group levels in opposite directions for hive stability.^[12]

Under ordinary circumstances, the death or removal of a queen is sufficient to increase reproduction in workers. A significant proportion of the 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. During this period, worker policing is noticeably absent. However, in certain groups of bees, worker policing continues.^[13]

According to kin selection theory, worker policing is not favored if a queen does not mate multiply. Workers would be related by three-quarters of their genes, and so the difference in relatedness between the sons of the queen and those of the other workers would decrease. Thus, the benefit obtained by policing is negated. Under these circumstances, 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.^[14]

Genome[edit]

The European honey bee is the third insect, after the fruit fly and the mosquito, to have its genome mapped. According to the scientists who analysed its genetic code, the honey bee originated in Africa and spread to Europe in two ancient migrations.^[2] They have also discovered the number of genes related to smell outnumber those for taste, and they have fewer genes for immunity than the fruit fly and the mosquito.^[15] The genome sequence revealed several groups of genes, particularly the genes related to circadian rhythms, were closer to vertebrates than other insects. Genes related to enzymes that control other genes were also vertebrate-like.^[16]

The genome is unusual in having very few transposons, while they have been present in the evolutionary past (inactive remains were found) and in general evolved slower than in Diptera species.^[15]

Pheromones[edit]

Honey bees use special pheromones, or chemical communication, for almost all behaviors of life. Such uses include (but are not limited to): mating, alarm, defense, orientation, kin and colony recognition, food production, and integration of colony activities. Pheromones are thus essential to honey bees for their survival.

Communication[edit]

A large honey bee swarm on a fallen tree trunk

Honey bees are an excellent animal species to study with regard to behavior because they are abundant and familiar to most people. Karl von Frisch, who was awarded the Nobel Prize for physiology and medicine in 1973 for his study of honey bee communication, noticed bees communicate through the language of dance. Honey bees are able to direct other bees to food sources through the round dance and the waggle dance. The round dance tells the other foragers that food is within 50 meters of the hive, but it does not provide much information regarding direction. The waggle dance, which may be vertical or horizontal, provides more detail about both the distance and the direction of the located food source. Bees also are thought to rely on their olfactory sense to help locate the food source once the foragers are given directions from the dances.

Another signal for communication is the shaking signal, also known as the jerking dance, vibration dance, or vibration signal. It is a modulatory communication signal because it appears to manipulate the overall arousal or activity of behaviors. The shaking signal is most common in worker communication, but it is also evident in reproductive swarming. A worker bee vibrates its body dorsoventrally while holding another honey bee with its front legs. Jacobus Biesmeijer examined the incidence of shaking signals in a forager's life and the conditions that led to its performance to investigate why the shaking signal is used in communication for food sources. Biesmeijer found that the experienced foragers executed 92.1% of the observed shaking signals. He also observed that 64% of the shaking signals were executed by experienced foragers after they had discovered a food source. About 71% of the shaking signal sessions occurred after the first five foraging success within one day. Then other communication signals, such as the waggle dance, were performed more often after the first five successes. Biesmeijer proved that most shakers are foragers and that the shaking signal is most often executed by foraging bees over pre-foraging bees. Beismeijer concluded that the shaking signal presents the overall message of transfer work for various activities or activity levels. Sometimes the signal serves to increase activity, when bees shake inactive bees. At other times, the signal serves as an inhibitory mechanism such as the shaking signal at the end of the day. However, the shaking signal is preferentially directed towards inactive bees. All three types of communication between honey bees are effective in their jobs with regards to foraging and task managing.

"The general story of the communication of the distance, the situation, and the direction of a food source by the dances of the returning (honey bee) worker bee on the vertical comb of the hive, has been known in general outline from the work of Karl von Frisch in the middle 1950s."

Beekeeping[edit]

A queen bee with workers

The honey bee is a colonial insect that is often maintained, fed, and transported by beekeepers. Honey bees do not survive individually, but rather as part of the colony. Reproduction is also accomplished at the colony level. Colonies are often referred to as superorganisms.

Honey bees collect flower nectar and convert it to honey which is stored in their hives. The nectar is transported in the stomach of the bees, and is converted to honey through the addition of various digestive enzymes, and by being stored in a "honey cell" and then partially dehydrated. Nectar and honey provide the energy for the bees' flight muscles and for heating the hive during the winter period. Honey bees also collect pollen which supplies protein and fat for bee brood to grow. Centuries of selective breeding by humans have created honey bees that produce far more honey than the colony needs. Beekeepers, also known as "apiarists," harvest the honey.

Beekeepers often provide a place for the colony to live and to store honey. There are seven basic types of beehive: skeps, Langstroth hives, top-bar hives, box hives, log gums, D.E. hives and miller hives. All U.S. states require beekeepers to use movable frames to allow bee inspectors to check the brood for disease. This allows beekeepers to keep the Langstroth, top-bar, and D.E. hives freely, but other types of hives require special permitting, such as for museum use. The type of beehive used significantly impacts colony health and wax and honey production.

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.

In cold climates some beekeepers have kept colonies alive (with varying success) by moving them indoors for winter. While this can protect the colonies from extremes of temperature and make winter care and feeding more convenient for the beekeeper, it can increase the risk of dysentery (see the Nosema section of diseases of the honey bee) and can create an excessive buildup of carbon dioxide from the respiration of the bees. Recently, inside wintering has been refined by Canadian beekeepers, who build large barns just for wintering bees. Automated ventilation systems assist in the control of carbon dioxide build-up.

Breeding[edit]

Numerous traits are present in the various subspecies of honeybees that are amenable to selection via breeding. This listing covers a small part of the variation present in the honeybee genome.

1. Egg Laying Rate – Queen can lay a few hundred eggs per day up to about 5,000 eggs per day.

2. Egg Viability Rate – Can range from 0 up to 100% of eggs that hatch and develop into bees.

3. Brood Cycle Length – For worker bees ranges from 17 days up to 21 days.

4. Brood Nurturing – This is a measure of how intent the nurse bees are at nurturing brood.

5. Foraging Aggressiveness – This trait determines potential for honey production.

6. Time Of Foraging – Some bees forage earlier in the day and later in the evening than others.

7. Disease Resistance – This is a measure of innate tolerance to brood diseases and adult diseases.

8. Pest Resistance – This is a measure of innate tolerance to pests such as tracheal and varroa mites.

9. Defensive Behavior – Determines aggressiveness and stinging propensity.

10. Swarming Tendency – This determines the timing and success of colony reproduction.

11. Winter Hardiness – Clustering behavior and ability to survive extended low temperatures.

12. Life Span – Ranges from a 22 days up to 305 days for workers with an average of 36 days.

13. Body Size – Small bees are typical in Africa with larger bees typical in colder climates.

14. Sense Of Smell – Ability to detect flower odors and respond to nectar availability.

15. Hygienic Cleaning Behavior – This is a major component of both disease and pest resistance.

16. Time Of Brood Development – Bees must begin brood rearing at least 8 weeks before nectar flows.

17. Thrift – Adjustment of brood production to available food sources for efficient use of resources.

18. Honey Arrangement – Storing honey closer to or further away from the brood next.

19. Pollen Collection – Amount and floral source of pollen are under direct genetic control.

20. Type Of nectar Collected – This has a major impact on honey quality and value.

21. Comb Building – Willingness to build comb and expand the colony.

22. Capping Structure – Ranges from flat and watery to gray to white dome shaped cappings.

23. Propolis Collection – Associated with wintering success, ranges from none to covering all hive surfaces.

24. Brace Comb Construction – Ranges from very little to cross comb throughout the colony.

25. Abdominal Color – Ranges from black to various color stripes in tan, yellow, and orange.

26. Antennae Structure – Number and placement of sensors is inherited, associated with sense of smell.

27. Number of Drones Produced – Ranges from very few up to ¼ of brood combs.

28. Number of Queens Produced – Ranges from a few up to several hundred.

Products[edit]

Honey bees[edit]

One of the primary products is more honeybees. Honey bees are bought and sold as mated queens, in spring packages of a queen with 2 to 5 pounds of bees, as nucleus colonies which include frames of brood, and as full colonies of bees. Commercial sale of bees dates to prehistory. Modern methods of producing queens and dividing colonies for increase date to the late 1800s. Bees are typically produced in temperate to tropical regions and sold to colder areas, as for example packages of bees produced in Florida and sold to beekeepers in Michigan.

Pollination[edit]

Beehives set up for pollination

The honey bee's primary commercial value is as a pollinator of crops. Orchards and fields have grown larger; at the same time wild pollinators have dwindled. In several areas of the world the pollination shortage is compensated by migratory beekeeping, with beekeepers supplying the hives during the crop bloom and moving them after bloom is complete. In many higher latitude locations it is difficult or impossible to winter over enough bees, or at least to have them ready for early blooming plants, so much of the migration is seasonal, with many hives wintering in warmer climates and moving to follow the bloom to higher latitudes.

As an example, in California, the pollination of almonds occurs in February, early in the growing season, before local hives have built up their populations. Almond orchards require two hives per acre (2,000 m² per hive) for maximum yield and so the pollination is highly dependent upon the importation of hives from warmer climates. Almond pollination, which occurs in February and March, is the largest managed pollination event in the world, requiring more than one third of all the managed honey bees in the United States. Massive movement of honey bee are also made for apples in New York, Michigan, and Washington. And despite the inefficiency of honey bees in pollinating blueberries,^[17] huge numbers are also moved to Maine for blueberries, because they are the only pollinators that can be relatively easily moved and concentrated for this and other monoculture crops. Commercial beekeepers plan their movements and their wintering locations with prime reference to the pollination services they plan to perform.

Honey bees immersed in yellow beavertail cactus pollen, in the High Desert of California

Bees, as well as some other insects, are particularly beneficial as pollinators to most plants, as they maintain flower constancy, which means they are more likely to transfer pollen to other conspecific plants.^[18] Also, flower constancy prevents the loss of pollen during interspecific flights and pollinators from clogging stigmas with pollen of other flower species.^[19]

Honey[edit]

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. Honey is a complex biological mixture that consists mostly of inverted sugars, primarily glucose and fructose. It has antibacterial and antifungal properties and will not rot or ferment when stored under normal conditions. However, honey will crystallize with time. Crystallized honey is not damaged or defective in any way, for human use, but bees will automatically remove crystallized honey from their hive and discard it, since they can only use liquid honey.

The bee carries pollen in a pollen basket back to the hive

Beeswax[edit]

Worker bees of a certain age will secrete beeswax from a series of glands on their abdomen. They use the wax to form the walls and caps of the comb. When honey is harvested, the wax can be gathered to be used in various wax products like candles and seals.

See movie of bee at work collecting pollen. Requires an Ogg Theora enabled browser or player, such as Firefox or VideoLAN.

Pollen[edit]

Bees collect pollen in the pollen basket and carry it back to the hive. There, pollen is used as a protein source necessary during brood-rearing. In certain environments, excess pollen can be collected from the hives. It is often eaten as a health supplement.

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

Propolis[edit]

Propolis is a resinous mixture that honey bees collect from tree buds, sap flows, or other botanical sources. It is used as a sealant for unwanted open spaces in the hive. Propolis is marketed for its alleged health benefits, but may cause severe allergic reactions in some individuals.

Royal jelly[edit]

Royal jelly is a honey bee secretion that is used in the nutrition of the larvae. It is marketed for its alleged health benefits, but may cause severe allergic reactions in some individuals.

Hazards and survival[edit]

European honey bee populations have recently faced threats to their survival. North American and European populations were severely depleted by varroa mite infestations in the early 1990s, and US beekeepers were further affected by colony collapse disorder in 2006 and 2007.^[20] Chemical treatments against Varroa mites saved most commercial operations and improved cultural practices. New bee breeds are starting to reduce the dependency on miticides (acaracides) by beekeepers. Feral bee populations were greatly reduced during this period but now are slowly recovering, mostly in areas of mild climate, owing to natural selection for Varroa resistance and repopulation by resistant breeds. Further, insecticides, particularly when used in violation of label directions, have also depleted bee populations^{[citation needed]}, while various bee pests and diseases are becoming resistant to medications (e.g. American foulbrood, tracheal mites and Varroa mites).

Environmental hazards[edit]

A bee swarm. Bees are remarkably non-aggressive in this state as they have no hive to protect, and can be captured with ease.

In North America, Africanized bees have spread across the southern United States where they pose a small danger to humans, although they may make beekeeping difficult and potentially dangerous (particularly hobby beekeeping).

As an invasive species, feral honey bees have become a significant environmental problem in places where they are not native. Imported bees may compete with and displace native bees and birds, and may also promote the reproduction of invasive plants that native pollinators do not visit. Also, unlike native bees, they do not properly extract or transfer pollen from plants with poricidal anthers (anthers that only release pollen through tiny apical pores), as this requires buzz pollination, a behavior which honey bees rarely exhibit. For example, honey bees reduce fruiting in Melastoma affine (a plant with poricidal anthers) by robbing stigmas of previously deposited pollen.^[21]

Predators[edit]

Insects[edit]

• Asian giant hornet - Southeast Asia
• Robber flies
• Dragonfly
  • Green Darner
• European beewolf - Europe and North Africa
• Chinese mantis
• Bald-faced hornet
• Common water strider
• Yellowjacket

Spiders[edit]

• Six-spotted fishing spider
• Green lynx spider
• Goldenrod spider ^[22]
• Black argiope

Reptiles and amphibians[edit]

• American toad
• Anoles
• Bullfrog
• Wood frog

Birds[edit]

• Bee-eater
• Common grackle
• Ruby-throated hummingbird
• Tyrant flycatcher
• Great Crested Flycatcher

Mammals[edit]

Contrary to popular perception, bears and honey badgers are brood predators; honey is only of secondary interest.

• Bear
• Human
• Least shrew
• Opossum
• Raccoon
• Honey badger
• Skunk

Designated state insect[edit]

See also[edit]

• Bee sting therapy
• Beeline
• Bee bearding
• Ecological importance of bees
• Worker policing

References[edit]

Bibliography[edit]

The Buckfast bee is a strain of honey bee. It is a hybrid, a cross of many strains of bees, developed by "Brother Adam", (born Karl Kehrle on 3 August 1898 in Germany), who was in charge of beekeeping at Buckfast Abbey, where the bees are still bred today. Most of the breeding work in Europe is done by breeders belonging to the breeders accociation "Gemeinschaft der Europäischen Buckfastimker". This organisation is maintaining a pedigree for Buckfast bees, originating from Brother Adam's years.

Origin

In the early 20th century bee populations were being decimated by Isle of Wight disease. This condition, later called "acarine" disease, after the acarine parasitic mite that invaded the bees' tracheal tubes and shortened their lives, was killing off thousands of colonies in the British Isles in the early part of the 20th century.^[1]

In 1916 there were only 16 surviving colonies in the Abbey. All of them were either pure Ligurian (Italian) or of Ligurian origin, hybrids between Ligurian and the English black bee A.m. mellifera. Brother Adam also imported some more Italian queens. From these he began to develop what would come to be known as the Buckfast bee.

Heritage

The Buckfast contains heritage from mainly A.m. ligurica (North Italian), A.m. mellifera (English), A.m. mellifera (French), A.m. anatolica (Turkish) and A.m. cecropia (Greek). The Buckfast bee of today also contains heritage from two rare and docile African stocks A. m. sahariensis and the A.m. monticola, but not the "Africanized" A. m. scutellata. "^[2]

History

Brother Adam moved the bees he discovered to the isolated valley of Dartmoor which became a mating station for selective breeding. With no other bees within range, Brother Adam could maintain their genetic integrity and develop desirable traits.

Brother Adam investigated various honey bee races and made many long journeys in Europe, Africa and the Middle-East searching for pure races and interesting local stocks. The book In Search of the Best Strains of Bee tells about his travels in search of genetic building blocks. Brother Adam imported more bees to cross with his developing Buckfast bee.

Every new bee strain or bee race was first crossed with the existing Buckfast Bee. In most cases, the new desired qualities were passed on to the new generation and the new combination was then made stable with further breeding work. Every crossing with a new race took about 10 years before the desired genes were fixed in the strain. Over seventy years, Brother Adam managed to develop a vigorous, healthy, and fecund honey bee which he christened the Buckfast bee.

The Buckfast bee is popular among beekeepers and is available from bee breeders in Germany, Ireland, the United Kingdom, France, and more. Most of the Buckfast bee's qualities are very favorable. They are extremely gentle and highly productive. Brother Adam, in his book, Beekeeping at Buckfast Abbey writes that in 1920 they obtained "an average of no less than 192 lbs surplus per colony and individual yields exceeding 3 cwt [approx. 336 lbs]. "^[3] In the 1986 BBC-affiliated documentary, The Monk and the Honey Bee, more than 400 pounds of honey are reported to have been produced by a single Buckfast colony. According to Brother Adam, "The average annual honey yield over the last thirty years has been 30 kg (66 lb.) per colony. Thus we have a favourable balance compared with the average production in America or in Europe. "^[4][5]

The stock has been imported into the United States (eggs, semen, and adult queens via Canada) and they are easily available.^[6]

Buckfast Breeding Program

The qualities and characteristics desired in Brother Adam's breeding can be divided into three groups; Primary, Subsidiary, and 3rd, those that have bearing on management.

Primary

Primary qualities are those qualities essential for any maximum honey production.

• Fecundity - maintaining at least 9 frames of brood May - July
• Foraging zeal - a boundless capacity for foraging work, close inbreeding to intensify this quality can be counter-productive.
• Resistance to disease
• Disinclination to swarm

Subsidiary

• Longevity
• Wing-power
• Keen sense of smell
• Defensive characteristics
• Hardiness and ability to over winter
• Spring development
• Thrift
• Instinct of self provisioning
• Arrangement of honey stores
• Wax production and comb building
• Gathering of pollen
• Tongue-reach

Qualities which Influence Management

• Good temper
• Calm behavior
• Disinclination to propolize
• No brace combs
• Cleanliness
• Honey capping
• Sense of orientation^[7][8]

Characteristics

Strong Points

• Good honey producer
• Prolific queens (lay many eggs)
• Overwinters well
• Frugal - Low amount of brood during fall (uses less honey stores during winter)
• Packs brood nest with honey for good wintering
• Curtails egg laying during dearths
• Brood rearing ceases during late fall
• Extremely gentle, with low sting instinct
• Low swarm instinct
• High Tracheal Mite Tolerant
• Low incidence of chalkbrood and wax moths due to good housecleaning techniques
• Very hygienic
• Build-up rapidly once started
• Produces little propolis/brace comb^[9]
• Does well in cold/wet spring

Weak Points

• Low amount of brood during Winter
• Less honey or pollen due to erratic spring weather conditions
• Possibility of second generation defensiveness if not requeened
  • This is not due to being a "second generation" hybrid. The Buckfast is a mix of many, many generations with many different species. A likely cause of "hot" hives in subsequent generations is the introduction of Africanized bee genetics being introduced either to the mother queen or to the daughter queen via local Africanized drones. Buckfast bees in cooler regions where Africanized bees have not arrived do not have this problem.

Significance

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References