Stingless bees, or simply meliponines, are a large group of bees, comprising the tribe Meliponini (sometimes called stingless honey bees) in the family Apidae, and closely-related to the common honey bees, carpenter bees, orchid bees and bumblebees. The common name is slightly misleading, as a great many bee species, especially in the family Andrenidae, are incapable of stinging, as are all male bees. It is also true that meliponines do not lack stings morphologically; they are simply highly reduced and cannot be used for defense.
Stingless bees can be found in most tropical or subtropical regions of the world, such as Australia, Africa, Southeast Asia, and parts of Mexico and Brazil. The majority of native eusocial bees of Central and South America are stingless bees, although only a few of them produce honey on a scale such that they are farmed by humans. They are also quite diverse in Africa and are farmed there also; meliponine honey is prized as a medicine in many African communities.
Being tropical, stingless bees are active all year round, although they are less active in cooler weather. Unlike other eusocial bees, they do not sting but will defend by biting if their nest is disturbed. In addition, a few (in the genus Oxytrigona) have mandibular secretions that cause painful blisters. Despite their lack of a sting, stingless bees, being eusocial, may have very large colonies made formidable by way of numerous defenders.
Stingless bees usually nest in hollow trunks, tree branches, or rock crevices but they have also been encountered in wall cavities, old rubbish bins, water meters, and storage drums. Many beekeepers keep the bees in their original log hive or transfer them to a wooden box, as this makes it easier to control the hive.
The bees store pollen and honey in large egg-shaped pots made of beeswax, typically mixed with various types of plant resin (sometimes called "propolis"). These pots are often arranged around a central set of horizontal brood combs, where the larval bees are housed. When the young worker bees emerge from their cells, they tend to remain inside the hive, performing different jobs. As workers age, they become guards or foragers. Unlike honey bees, meliponine larvae are not fed directly. The pollen and nectar are placed in a cell, an egg is laid, and the cell is sealed until the adult bee emerges after pupation ("mass provisioning"). At any one time, hives can contain anywhere from 300-80,000 workers, depending on species.
In a simplified sense, the sex of each bee depends on the number of chromosomes it receives. Female bees have two sets of chromosomes (diploid) - one set from the queen and another from one of the male bees or drones. Drones have only one set of chromosomes (haploid), and are the result of unfertilized eggs, though inbreeding can result in diploid drones.
Unlike true honey bees, whose female bees may become workers or queens strictly depending on what kind of food they receive as larvae (queens are fed royal jelly and workers are fed pollen), the caste system in meliponines is variable, and commonly based simply on the amount of pollen consumed; larger amounts of pollen yield queens in the genus Melipona. There is also a genetic component however, and as much as 25% (typically 5-14%) of the female brood may be queens. Queen cells in the former case can be distinguished from others by their larger size, as they are stocked with more pollen, but in the latter case the cells are identical to worker cells, and scattered among the worker brood. When the new queens emerge, they typically leave to mate, and most die. New nests are not established via swarms, but by a procession of workers who gradually construct a new nest at a secondary location. The nest is then joined by a newly-mated queen, at which point many workers take up permanent residence and help the new queen raise her own workers. If a ruling queen is herself weak or dying, then a new queen can replace her. For Plebeia quadripunctata, although less than 1% of female worker cells produce dwarf queens, they comprise six out of seven queen bees, and one out of five proceed to head colonies of their own. They are reproductively active but less fecund than large queens.
As stingless bees are harmless to humans, they have become an increasingly attractive addition to the suburban backyard. Most meliponine beekeepers do not keep the bees for honey but rather for the pleasure of conserving a native species whose original habitat is declining due to human development. In return, the bees pollinate crops, garden flowers, and bushland during their search for nectar and pollen.
While a number of beekeepers fill a small niche market for bush honey, native meliponines only produce small amounts and the structure of their hives makes the honey difficult to extract. It is only in warm areas of Australia such as Queensland and northern New South Wales that the bees can produce more honey than they need for their own survival. Harvesting honey from a nest in a cooler area could weaken or even kill the nest.
In warm areas of Australia, these bees can be used for minor honey production. They may also be kept successfully in boxes in these areas. Special methods are being developed to harvest moderate amounts of honey from stingless bees in these areas without causing harm.
Like the European honey bee (Apis mellifera) which provides most of Australia's commercially-produced honey, stingless bees have enlarged areas on their back legs for carrying pollen back to the hive. After a foraging expedition, these pollen baskets or corbiculae can be seen stuffed full of bright orange or yellow pollen. Stingless bees also collect nectar, which they store in an extension of their gut called a crop. Back at the hive, the bees ripen or dehydrate the nectar droplets by spinning them inside their mouthparts until honey is formed. Ripening concentrates the nectar and increases the sugar content, though it is not nearly as concentrated as the honey from true honey bees; it is much thinner in consistency, and more prone to spoiling.
Stingless bees store their aromatic honey in clusters of small resin pots near the extremities of the nest. For honey production, the bees need to be kept in a box specially designed to make the honey stores accessible without damaging the rest of the nest structure. Some recent box designs for honey production provide a separate compartment for the honey stores so that honey pots can be removed without spilling honey into other areas of the nest.
Unlike a hive of commercial honeybees, which can produce 75 kilograms of honey a year, a hive of Australian stingless bees produces less than one kilogram. Stingless bee honey has a distinctive "bush" taste - a mix of sweet and sour with a hint of fruit. The taste comes from plant resins - which the bees use to build their hives and honey pots - and varies at different times of year depending on the flowers and trees visited.
Australian farmers rely heavily on the introduced Western honey bee to pollinate their crops. However, for some crops native bees may be better pollinators. Stingless bees have been shown to be valuable pollinators of crops such as macadamias and mangoes. They may also benefit strawberries, watermelons, citrus, avocados, lychees and many others. Research into the use of stingless bees for crop pollination in Australia is still in its very early stages, but these bees show great potential. Recent studies at the University of Western Sydney (see Aussie Bee, Issue 10) have shown these bees' excellent ability to work in confined areas such as glasshouses.
The stingless bees Melipona beecheii and M. yucatanica are the only native bees cultured to any degree in the Americas. They were extensively cultured by the Maya for honey, and regarded as sacred. These bees are endangered due to massive deforestation, altered agricultural practices (especially insecticides), and changing beekeeping practices with the arrival of the Africanized honey bee, which produces much greater honey crops.
Native meliponines (Melipona beecheii being the favorite) have been kept by the lowland Maya for thousands of years. The traditional Mayan name for this bee is Xunan kab, literally meaning "royal lady". The bees were once the subject of religious ceremonies and were a symbol of the bee-god Ah Muzen Cab, who is known from the Madrid Codex.
The bees were, and still are, treated as pets. Families would have one or many log-hives hanging in and around their house. Although they are stingless, the bees do bite and can leave welts similar to a mosquito bite. The traditional way to gather bees, still favored amongst the locals, is to find a wild hive; then the branch is cut around the hive to create a portable log, enclosing the colony. This log is then capped on both ends with another piece of wood or pottery and sealed with mud. This clever method keeps the melipine bees from mixing their brood, pollen, and honey in the same comb as the European bees. The brood is kept in the middle of the hive, and the honey is stored in vertical "pots" on the outer edges of the hive. A temporary, replaceable cap at the end of the log allows for easy access to the honey while doing minimal damage to the hive. However, inexperienced handlers can still do irreversible damage to a hive, causing the hive to swarm and abscond from the log. On the other hand, with proper maintenance, hives have been recorded as lasting over 80 years, being passed down through generations. In the archaeological record of Mesoamerica, stone discs have been found which are generally considered to be the caps of long-disintegrated logs which once housed the beehives.
Tulum, the site of an ancient Mayan city on the Caribbean coast 130 km south of Cancun, has a god depicted repeatedly all over the site. Upside down, he appears as a small figure over many doorways and entrances. One of the temples, the "Templo del Dios Descendente" or the Temple of the Descending God, stands just left of the central plaza. Speculation is that he may be the "Bee God", Ah Muzen Cab, as seen in the Madrid Codex. It is possible that this was a religious/trade center with emphasis on Xunan kab, the "royal lady".
Balché, an alcohol beverage similar to mead, was made from fermented honey and the bark of the Balché tree, hence its name. It was traditionally brewed in a canoe. The drink was known to have entheogenic properties, (that is, it produces mystical experiences,) and was consumed in medicinal and ritual practices. The hallucinogenic properties come from the alkaloid bark of the leguminous Balché tree (Lonchocarpus violaceus), although whether the hallucinogens came from the bark or the honey, which beekeepers would harvest after placing the nests near the trees, remains uncertain. Toxic and hallucinogenic substances can be found in honey if bees collect nectar and pollen from certain types of vegetation. Most likely, it is a combination of the two, since balché is made from both the Melipona honey from the Balché flowers, and the bark of the tree, brewed and fermented together.
Lost wax casting, a common metalworking method which is typically found where the inhabitants keep bees, was also utilized by the Maya. The wax from Melipona is soft and easy to work, especially in the humid Mayan lowland areas. This allowed the Maya to create smaller works of art, jewelry, and other metalsmithing that would be difficult to forge. It also makes use of the leftovers from honey extraction. If the hive was damaged beyond repair, the whole of the comb could be used, thus using all of the hive. With experienced keepers, though, only the honey pot could be removed, the honey extracted, and the wax used for casting or other purposes.
The outlook for meliponines in Mesoamerica is grim. The number of active Melipona beekeepers is rapidly declining in favor of the more economical, non-indigenous Africanized Apis mellifera. The high honey yield, 100 kilograms or more annually, along with the ease of hive care and ability to create new hives from existing stock, commonly outweighs the negative consequences of "killer bee" hive maintenance. Furthermore, there are flora that the Africanized honey bees do not visit, such as those in the tomato family, and several forest trees and shrubs, which rely on the native stingless bees for pollination. There has already been a decline in native populations of flora in areas where stingless bees have been displaced by Africanized honey bees. An additional blow to the art of meliponine beekeeping is that many of the meliponine beekeepers are now elderly men and women, whose hives may not be cared for once they die. The hives are considered similar to an old family collection, to be parted out once the collector dies or to be buried in whole or part along with the beekeeper upon death. In fact, a survey of a once-popular area of the Mayan lowlands shows the rapid decline of beekeepers, down to around 70 in 2004 from thousands in the late 1980s. It is traditional in the Mayan lowlands that the hive itself or parts of the hive be buried along with the beekeeper to volar al cielo, "to fly to heaven". There are conservation efforts underway in several parts of Mesoamerica. A comprehensive conservation guide can be found in the June 2005 issue of Bee World.