| Eastern honey bee | |
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| Asiatic honey bee -Khao Yai National Park,Thailand | |
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| Apis cerana workers and queen (marked with red dot) from hive near Chiang Mai, Thailand | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Hymenoptera |
| Family: | Apidae |
| Genus: | Apis |
| Species: | A. cerana |
| Binomial name | |
| Apis cerana Fabricius, 1793 | |
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| Range ofApis cerana | |
Apis cerana, theeastern honey bee,Asiatic honey bee orAsian honey bee, is a species ofhoney bee native toSouth,Southeast andEast Asia. This species is thesister species ofApis koschevnikovi and both are in the same subgenus as the western (European) honey bee,Apis mellifera.[1][2][3][4][5]A. cerana is known to livesympatrically along withApis koschevnikovi within the same geographic location.[6]Apis cerana colonies are known for building nests consisting of multiple combs in cavities containing a small entrance, presumably for defense against invasion by individuals of another nest.[7] The diet of this honey bee species consists mostly ofpollen andnectar, orhoney.[8] Moreover,Apis cerana is known for its highly social behavior, reflective of its classification as a type ofhoney bee.[4]
The termsApis cerana indica andApis Indica[9] or Indian honey bee,[10][11] is an historic term, with all Asian hive bees now referred to asApis cerana.[12]
Danish zoologistJohan Christian Fabricius describedApis cerana, also known as the eastern or Asian honey bee, in 1793.[2] The genus nameApis is Latin for "bee". The eastern honey bee is of theApidae family, one of the most diverse families of bees, includinghoney bees,carpenter bees,orchid bees,bumblebees,cuckoo bees, and evenstingless bees.[13]
In the past, there has been discussion thatApis cerana andApis mellifera are simply distinct races of the same species. This is essentially due to overwhelming similarities in bothmorphology and behavior, as both are medium-sized bees (10-11mm) that generally build multiple comb nests inside cavities. Otherhoney bee species, including the giant honey beesApis dorsata andApis laboriosa, generally construct nests consisting of a single comb in open areas.[14] However, despite the striking similarities betweenApis cerana andApis mellifera, there is evidence to suggest that these two species are quite distinct; for example, mating between these species does not produce offspring. In addition, whileApis mellifera colonies can reach sizes of up to 50,000 or more individuals,Apis cerana colonies are relatively small, with only around 6,000 to 7,000 workers.[14] Moreover,Apis cerana is found predominantly in the Eastern Asian region of the world, whileApis mellifera is found predominantly in the Western European and African region of the world.[14] For these reasons, it has now been concluded that these are in fact two separate species, contrary to prior beliefs.
Historically,Apis cerana has been subdivided into eight subspecies according toEngel (1999); they are:
Recent genetic analysis, however, has determined that some of the subspecies described may have been inadvertent misidentifications of very similarsympatric species, includingApis koschevnikovi ofBorneo andApis nigrocincta of thePhilippines.Apis cerana nuluensis of Borneo is also now generally considered to be a separate species, asApis nuluensis.[16]
Radloffet al. (2010) have instead chosen to subdivideApis cerana into six main statistically defined populations based onmorphotypes ("morphoclusters"), instead of infraspecific ranks, which they argue were invalidly established and not biologically meaningful. These morphoclusters are:[16]
The physical characteristics ofApis cerana individuals are very similar to those of other species in the genusApis. The individuals in this genus are defined by long, erect hairs that cover the compound eyes and assist in pollen collection, strongly convexscutellum, and a jugal lobe in thehindwing. AdultApis cerana are black in color, with four yellow abdominal stripes. There are also distinctions between worker bees, queens, and drones.Worker bees are characterized by a pollen press on the hind leg to transport pollen, as well as a stinger in the place of an organ for laying eggs. Queens, which are the reproductive females, are typically larger than worker bees due to their enlarged reproductive organs. Drones, which are the males of the species, are defined by larger eyes, lack of astinger, and a blunter abdominal shape.[4]
Apis cerana encompass a wide range of climatic zones including moisttropical rainforests, wet-dry tropical savannas, mid-latitudesteppes, dry mid-latitudegrasslands, moist continentaldeciduous forests, andtaigas.[16] The natural range ofApis cerana extends fromPrimorsky Krai inRussia in the north, toeastern Indonesia in the south; and toJapan in the east, to as far as the highlands ofAfghanistan in the west. Countries they are native to includeAfghanistan,Bangladesh,Bhutan,Brunei,Cambodia,China,India,Indonesia,Japan,Laos,Malaysia,Myanmar,Nepal,North Korea,Pakistan, thePhilippines,Russia,South Korea,Sri Lanka,Taiwan,Thailand,Timor-Leste, andVietnam. It was introduced deliberately toNew Guinea in the 1970s, and has since spread into theTorres Strait Islands intoAustralia and theSolomon Islands.[17][16][18] Although the species was naturally clustered in East Asia, it has now expanded to various regions across the world as a result of human interference, with particular concern about its invasive potential in Australia as nests are found in a variety of environments, including both natural and man-made (see below).[16]
As a type of honey bee,Apis cerana must collect and store around a third of itsnectar in a concentrated form in order to ensure an adequate supply for consumption during the harsh winter.[19] The nest is multi-combed and somewhat insulated, allowing the species to achieve optimal nest temperatures and thereby optimize foraging at early hours. The nest itself is a simple vertical comb made from wax secreted by workers, while thethermoregulation is generated by fanning and water evaporation from water collected in the field.[4] This large-scale storage tactic requires the construction of a stable and sturdycomb structure for such honey storage. However, as the production of beeswax for a comb is an energetically expensive endeavor, colonies do not generally build the entire structure very early on. Instead, the colony builds a smaller set of combs that satisfies the initial storage needs. Upon moving into the new nest, the colony will then continue to enlarge the combs until there are enough storage units to sufficiently account for all of the required honey. In general, the initial set of combs may account for around 20,000 cells, while the final, completed structure may contain up to 100,000.[19] These nests are typically large enough to host around 6,000 to 7,000 individuals and are found in a wide range of external environments.[14]
A. cerana maintains internal hive temperatures with a precision similar to that ofA. mellifera, using similar mechanisms.A. cerana maintain body temperatures in a range of 33–35.5 °C even while ambient temperatures vary between 12 and 36 °C. This mechanism clearly shows them to possess effective nestthermoregulation systems. During summer,A. cerana employs evaporative cooling, where the worker bees cluster outside the nest in hot weather and fan their wings, thus removing excess heat and moisture from the nest and decreasing the hive temperature.
When anA. cerana hive is invaded by the Japanese giant hornet (Vespa mandarinia), about 500 Japanese honey bees (A. cerana japonica) surround the hornet and vibrate their flight muscles until the temperature is raised to 47 °C (117 °F), heating the hornet to death, but keeping the temperature still under their own lethal limit (48–50 °C).[20][21]
The colony ofApis cerana, a typicalhoney bee, consists of several thousand female worker bees, one queen bee, and several hundred male drone bees. The colony is constructed inside beeswax combs inside a tree cavity, with a special peanut-shaped structure on the margins of the combs where the queens are reared.[19]
The colony's annual cycle in cold temperature regions begins shortly after the winter solstice, when the colony raises the core temperature of its cluster to about 34 degrees Celsius and starts to rear brood. At first, only around 100 bees are produced, but several thousand bees are developing by early spring. By late spring, the colony will have already attained full size, and will begin to reproduce. The colony then rears several new queens, and divides itself with about half the workers plus the old queen once the new queens have nearly matured. This new swarm then flies to a new tree branch, explores nest cavities, and then directs the other bees to the new site once satisfied with the location.[19]
During the remainder of summer and into the fall, the colonies in the new locations build combs, rear brood, and gather food to quickly rebuild their populations and food reserves prior to the arrival of winter.[19]
As a social species,Apis cerana colonies contain divisions of labor depending on what each member of the group is specialized to perform. There is generally only one queen bee whose sole responsibility it is to lay eggs; therefore, she is the mother of all the workers present in the colony. Apart from the queen bee, the remaining female bees are known as the worker bees, as these individuals perform all the tasks necessarily to maintain the hive including tending to the eggs, larvae, and pupae, foraging for food and water, cleaning the beehive and producing honey. These tasks are divided among the female worker bees by a factor of age. The remaining individuals are the males, known as the “drones,” whose only responsibility is to mate with a queen from another colony; therefore, drones are solely produced during the reproductive season.
The principal method of communication is thewaggle dance, performed primarily when a worker bee discovers a rich source ofpollen ornectar and wishes to share this knowledge with her fellow nest-mates. Thewaggle dance occurs deep inside the colony's hive, where the worker bee performs a brief reenactment of the recent journey to a patch of flowers. Neighboring bees observe and learn this dance and can then follow the same pattern, utilizing the odor of the flowers to fly in a certain path and arrive at the same destination. The bees following the informed worker bee will extend theirantennae towards the dancer in order to detect the dance sounds, as the frequency of the bee's antennae closely matches thevibrationfrequency of its wings.[19] The overall direction and duration of each waggle is closely correlated with the direction and distance from the flower patch being described.[19]
Within thehoney bee colony, a queen bee typically mates with 10 or more males.[19] This extensive mating is performed in an effort to secure a great range of genetic variation in her colony to cope with diseases, as well as respond to nectar sources and a wide range of external stimuli.[19] Apart from the queen bee, the only other sexual members of the society are the male drones, whose only function is to mate with the queen, after which they will die.[14]
The exact time and place ofApis cerana mating is specific to the subspecies, often varying by local environment. For instance, inSri Lanka,Apis cerana males typically aggregate beside a tree canopy as opposed to above a tree as is found in theApis cerana subspecies ofJapan. The most significant factor in determining mating time, however, is not ecological conditions, but rather the presence of drones of other species. Mating time decreases as the number of non-species drones present increases.[4]
InA. cerana, reproductive swarming is similar toA. mellifera.A. ceranareproductive swarms settle 20–30 m away from the natal nest (the mother or primary colony) and stay for a few days before departing for a new nest site after getting information from scout bees.[19] Scout bees search for suitable cavities in which to construct the swarm's home.[19] Successful scouts come back and report the location of suitable nesting sites to the other bees by performing communication dances on the surface of the swarm cluster in the same way as for food sources.[19]
A. cerana has migration and absconding behavior, abandoning the current nest and building a new nest in a new location where an abundant supply of nectar and pollen is available. These bees usually do not store great amounts of honey, so they are more vulnerable to starvation if a prolonged shortage of nectar and pollen occurs. Absconding will start when not enough pollen and nectar are available. After the last brood emerges, the adult bees fill their honey stomachs from the hive's stores and swarm to establish a new nest at a new location.A. cerana has more absconding behavior thanA. mellifera.
The development of worker bees in a colony is typical of that for any insect that undergoes completemetamorphosis as it includes the four stages ofegg,larva,pupa, andadult. Theembryo grows inside the egg for 3 days, consuming the protein-rich egg yolk.[19] Then it undergoes an 8-day larval stage, which is an intense feeding state involvinghoney,pollen, andbrood food supplied by the adult bees.[19] Finally, there is construction of a waxpupa which then matures and gnaws through the wax cap of the cell to emerge as a young bee.[19]
As one queen generally mates with over a dozen males, the genetic relatedness of the colony is biased and representshaplodiploidsex determination. If the queen bee lays unfertilized eggs with no paternal genetic contribution, the eggs will develop into drones. If the queen bee lays fertilized eggs with both maternal and paternal genetic contribution, the eggs will develop into females. In this system, virgin queens sharing the same father will have a genetic relatedness of 0.75 and those of different fathers will have a genetic relatedness of only 0.25.[19] The females workers in the colony are related to the queen's sons by a genetic relatedness of 0.25.[19] Such biasing results in the genes of some female worker bees being represented disproportionately in the virgin queens.[19]
Conflict may arise between workers and bees as female workers attempt to increase the propagation of their genes by biasing their queen-rearing efforts in favor of virgin queens sharing the same father. Although female worker bees do possessovaries and can essentially produce viable eggs, this potential is almost never realized as long as the colony is ruled by a dominant queen. Therefore, the probability of personal reproduction by a worker bee is exceedingly low. “Worker policing,” which is the mutual prevention of reproduction by workers, could be the reason behind the conscious non-reproduction of female worker bees.[19] In other words, their fertility is controlled by queen signals. The queen honey bee informs workers of her presence bypheromones that she secretes from her mandibular glands. These signals are acquired by workers in close proximity to the queen and then spread to other workers in the colony, mainly by physical contact. In the presence of queen pheromone signals, the vast majority of workers refrain from activating their ovaries. Due to factors of genetic relatedness, anApis cerana worker will often try to prevent other workers in her colony from reproducing, either by destroying worker-laid eggs, or by showing aggression towards workers attempting to lay eggs through worker policing.[19]
Adult worker bees predominantly feed on pollen and nectar or honey, though thenutritive value of pollen varies depending on the plant. Mixed pollens possess a high nutritive value and actually supply all the necessary materials for proper development of young animals. However, when dried, pollen quickly loses its nutritive value.[8]
In addition to feeding themselves, bees also feed each other through a process known as “food transmission.” Moreover, workers may also obtain food from the queen, while drones acquire food by ingesting material regurgitated by other drones. Queens themselves are fed larval food by the workers during their wintering season, thereby neither feeding on nor being fed honey.[8]
In addition to food requirements for diet, water also plays a key role in the growth and development of adult bees. In fact, the form of food has little to no influence on the longevity and life expectancy of the bee as long as there is ready availability of water.[8] This idea was further supported through experimental means concerning queen bees isolated in separate cages. Both groups were fed sugar candy as a control measure; however, the group that was fed water in addition to the sugar candy lived an average of two weeks or more compared to the other group which only survived a matter of three to four days.[8] Moreover, the importance of water intake for an adult bee's survival can be further understood through examination of diet and behavior during prime seasons, during which colonies of bees consume large amounts of water in order to dilute honey produced as well as to regulate temperature in the nest.[8]
Vespine wasps, endemic to Southeast Asia, are a major predator forApis cerana, predominantly at their colonies throughout Southern Asia. This hawking predation is especially fierce during theautumn season when the wasps are most populous, predominantly during the morning and afternoon. This method involves the wasps taking up a position in front of the beehive, while facing outwards away from the entrance towards returning foragers.[22] Vespine wasps attempt to attack the honey bee quarry in an effort to gain provisions to aid in the development of their own offspring.[22]
As the Vespine wasps approach the entrance to the honey bee nest, more guard bees are alerted, which in turn increases their probability of being killed by heat-balling bees. Heat balling is a unique defense system in which several hundred bees surround the wasp in a tight ball and vibrate their muscles in an effort to produce heat and effectively kill the wasp inside.[22] Alternatively, however, in the presence of a wasp, the bees may also just withdraw into their nests and await the heat-balling circumstances to develop naturally. Furthermore, other bees may just decide to fly away as an evasive measure in times of conflict, often altering their specific flight styles in order to avoidpredation.[22]
When anA. cerana hive is invaded by the Asian giant hornet (Vespa mandarinia), about 500 Japanese honey bees (A. cerana japonica) surround the hornet and vibrate their flight muscles until the temperature is raised to 47 °C (117 °F), heating the hornet to death, but keeping the temperature still under their own lethal limit (48–50 °C).[20]
Although bothApis mellifera andApis cerana suffer frompredation fromvespine wasps, one defense mechanism unique toApis cerana is “wing shimmering”.[22] During this period of self-defense, bees collectively execute carefully timed waves of shimmering of their wings when approached by predators such as vespine wasps.[22] This appears to serve as a distraction technique of visual pattern disruption that results in confusing predators.[22] As a result, predators are unable to continue attacking additional bees.
A 2020 study inVietnam found thatApis cerana usefeces and even human urine to defend their hives against raids by hornets (Vespa soror), a strategy not replicated by their European and North American counterparts,[23] though collection and use of feces in nest construction is well known instingless bees.[24][25]
Apis cerana is the natural host to themicrosporidian parasiteNosema ceranae, a seriouspest of the western honey bee.[26] When first discovered nearBeijing,China, in 1994, it was originally thought thatNosema ceranae was restricted toApis cerana in the East Asian region.[27] However, it has now been confirmed that this parasite species is actually present in colonies ofApis mellifera as well, both inTaiwan as well asSpain, though the origins of its arrival inEurope are still unknown.[27] Bees infected withNosema ceranae suffer reduced lifespans and increased mortality in the winter as well as poor buildup and reduced honey yield in the spring.[27]
Apis cerana has alsocoevolved with themiteVarroa jacobsoni and thus exhibits more carefulgrooming thanA. mellifera, thus has an effective defense mechanism againstVarroa that keeps the mite from devastating colonies. Other than defensive behaviors such as these, much of their behavior and biology (at least in the wild) is very similar to that ofA. mellifera.
Asian honey bees are often infected byChinese Sacbrood virus (CSBV) which also infectsA. mellifera.[28][29] Sacbrood viruses (SBV) primarily affect the brood of the honey bee and causes larval death.[30] Infected larvae fail topupate, and ecdysial fluid aggregates around the integument, forming the “sac” for which the disease is named. Infected larvae change in color from pearly white to pale yellow, and shortly after death they dry out, forming a dark browngondola-shaped scale.[31] SBV may also affect the adult bee, but in this case obvious signs of disease are lacking.[32][33]
Apis cerana was first detected in Australia in 2007. By 2012, it had spread across 500,000 hectares.[34] The impacts ofApis cerana on the Australian environment are not well known due to limited research.[35] However, according to Biosecurity Queensland (2103), theApis cerana "is likely to compete for pollen and nectar with native birds, mammals and insects, and for nesting sites in tree crevices".[36] There is a strong possibility thatApis cerana will also compete for resources with commercial honey bees and affect primary producers who rely on their pollination services. Control costs are also significant and amounted to at leastA$4 million up to 2011.[37]
Efforts to eradicateApis cerana in Australia have failed. Although an eradication program commenced in 2007, a decision that it was not possible to eradicateApis cerana was made in 2011.[35] The decision was controversial though, sparking a senate inquiry which concluded that it failed to apply theprecautionary principle and assess the potential impacts ofApis cerana on biodiversity.[38]
The bee is known as the Asian honey bee in Australia,[5] and is regarded as abiosecurity threat.[39]
As of 2015 the Biomodeling Laboratory atSeoul National University had constructed an Asian honey beetranscriptome database using an advanced sequencing technique.[40]
Authority control databases: National |
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