bee

Four-winged insect of the superfamily Apoidea in the order Hymenoptera, usually with a sting. There are over 12,000 species, of which fewer than 1 in 20 are social in habit. The hive bee or honeybee Apis mellifera establishes perennial colonies of about 80,000, the majority being infertile females (workers), with a few larger fertile males (drones), and a single very large fertile female (the queen). Worker bees live for no more than a few weeks, while a drone may live a few months, and a queen several years. Queen honeybees lay two kinds of eggs: fertilized, female eggs, which have two sets of chromosomes and develop into workers or queens, and unfertilized, male eggs, which have only one set of chromosomes and develop into drones.

Bees transmit information to each other about food sources by ‘dances’, each movement giving rise to sound impulses which are picked up by tiny hairs on the back of the bee's head, the orientation of the dance also having significance. They use the Sun in navigation (see migration). Besides their use in crop pollination and production of honey and wax, bees (by a measure of contaminants brought back to their hives) can provide an inexpensive and effective monitor of industrial and other pollution of the atmosphere and soil.

The most familiar species is the bumblebee, genus Bombus, which is larger and stronger than the hive bee and so is adapted to fertilize plants in which the pollen and nectar lie deep, as in red clover; they can work in colder weather than the hive bee.

Social bees, apart from the bumblebee and the hive bee, include the stingless South American vulture bee Trigona hypogea, discovered in 1982, which is solely carnivorous.

Solitary bees include species useful in pollinating orchards in spring, and may make their nests in tunnels under the ground or in hollow plant stems; ‘cuckoo’ bees lay their eggs in the nests of bumblebees, which they closely resemble.

The killer bees of South America are a hybrid type, created when an African subspecies of honeybee escaped from a research establishment in Brazil in 1957. They mated with, and supplanted, the honeybees of European origin in most of South and Central America, and by 1990 had spread as far north as Texas, USA. As well as being more productive and resistant to disease than European honeybees, they also defend their hives more aggressively, in larger numbers, and for a greater length of time than other honeybees. However, their stings are no more venomous, and although they have killed hundreds of thousands of animals and probably more than 1,000 people, most individuals survive an attack, and almost all deaths have occurred where the victim has somehow been prevented from fleeing.

Most bees are passive unless disturbed, but some species are aggressive. One bee sting may be fatal to a person who is allergic to them, but this is comparatively rare (about 1.5% of the population), and most adults can survive 300–500 stings without treatment. A vaccine treatment against bee stings, which uses concentrated venom, has been developed; see melitin.

In 1995 US scientists extracted bacterial spores from the gut of a bee fossilized in amber up to 40 million years ago. The spores were successfully germinated, and the resultant bacteria included a relative of a modern bacterium still found in the bee gut to aid digestion.

dangers and preservation Populations of honeybees are declining drastically worldwide due to the parasitic mite Varroa, which attaches itself to the bee's abdomen and sucks circulatory juices, infests brood chambers and feeds on grubs, and acts as a vector for disease. Commercial beekeepers in parts of the USA and a number of European countries were forced to destroy up to 80% of hives in 1990s. The US Department of Agriculture began breeding Varroa-resistant honeybees.

new discoveries A new genus of stingless bee was discovered in Central America in 1997. Meliwillea is found at high altitudes of 1,400–2,700 m in the cloudforests of Costa Rica and Panama.

In 2004 scientists announced the draft version of the honeybee genome to the public. The bee genome is a tenth of the size of the human genome, containing 300 million DNA base pairs.