Bee, external anatomy.
Bee, internal anatomy.
The bees in a hive are of three kinds: (1) the queen, (2) the male drone, and (3) the female worker. Pollen is the stuff of life to all of them; it is gathered by the worker in "baskets" on each hind leg (4).
The pollen-basket and brush are situated on the third and hindmost pair of legs of the bee. The pollen-basket is attached to the tibia, and, as its name indicates, it is the receptacle in which the bee stores the pollen it collects. The brush is situated on the next segment below the tibia and consists of numerous rows of hairs pointing downwards. The bee gathers pollen.
The bee's sucking apparatus consists of a long tongue or ligula, shaped like an open gutter the edges of which can join together to form a tube. On the end of the tongue there is a tuft of hair that acts like a sponge and absorbs the liquids on which the bee feeds; a bee can only take liquid food such as nectar from flowers.
A bee's compound eyes, ocelli, and antennae.
Bees have two pairs of wings, the hind ones smaller than the front. The front margin of the hind wings carries a series of minute hooks, by means of which the fore and hind wings are coupled in flight so that they act as a single wing. This increases the efficiency of the insect's flight. (1) The wings separated. (2) The wings locked together.
A bee in the process of producing wax. Eight little scales of wax are seen coming out of the insect's abdomen, and they are produced by glands placed between the abdominal segments. The wax is plucked off its body by the bee and molded in its jaws, and then used to build the symmetrical cells of the honeycomb.
A bee is a member of the superfamily Apoidea of insects. Bees convert nectar and pollen into honey for use as food. There are about 20,000 species. Bees and flowering plants (angiosperms) are largely interdependent; plants are pollinated (or fertilized) as the bees gather their pollen. Many farmers keep bees specially for this purpose.
Most bees are solitary and each female builds her own nest, although many bees may occupy a single site. Eggs are laid in cells provided with enough pollen-nectar paste to feed the larva until it becomes a flying, adult bee. Social bees (honey bees and bumblebees) live in a complex society of 10,000–50,000 members. Headed by the queen, whose function is to lay eggs (up to 2,000 a day), the community comprises female workers which collect pollen and build cells, and male bees, or drones, which fertilize the few young queens that appear each fall. Parasitic bees, not equipped to build hives, develop in the cells of the host working bees.
Both queen and workers come from the same larval stock. The sexual development of the few grubs chosen to replace the queen depends on their being fed a "royal jelly" produced by special glands of the worker nursemaids.
Anatomy of the bee
Like all insects the bee has three pairs of legs. With the first pair it continually brushes and cleans its antennae, whose extraordinary sensitivity would be impaired by the slightest speck of dirt. The second pair of legs is used almost entirely as a means of support. The pollen-basket and brush are on the third pair of legs.
Crop or honey-stomach
The nectar collected by the bee from the flowers she visits is stored in her crop and carried back to the hive. In the crop, chemical changes take place and the nectar is converted to honey. In the hive the honey is regurgitated and stored in the cells of the honeycomb.
These glands secrete a liquid which the worker bee regurgitates from its mouth to feed the larvae. Larvae that are destined to become queen bees receive an extra large quantity of it.
The bee, like other insects, does not breathe through its mouth, but through small openings situated along each side of the abdomen and thorax, called spiracles.
Dorsal blood vessel
The blood of the bee is a colorless liquid. The center of a bee's circulation is the dorsal vessel, a tubular sac which pulsates and so circulates the blood.
Ligula or tongue
The tongue of a bee is shaped like a trough and has a hairy pad at its tip, with which the bee sucks up liquids.
The abdomen contains the digestive organs and those of reproduction, respiration, and circulation. These connect with tubes called tracheae, which conduct the air to all parts of the body, and into a kind of air sac which functions as a lung.
Mandibles (jaws) and maxillae (accessory jaws)
These are used for chewing; for kneading the wax out of which the honeycomb is made; for opening the anthers of flowers; for cleaning out the hive; and for disabling enemies.
The antennae are important sense organs which are used by the bee to touch, measure, and smell.
The oceli are three small eyes located on the top of the bee's head and arranged in a triangle. They serve for vision at close quarters and in near darkness.
There is a pair of compound eyes, situated one on each side of the head. They give a panoramic view of faraway objects, magnified 60 times.
With its sting the bee injects a poisonous substance into the body of its enemy. It is used as a defense and is not normally dangerous to man. When it stings a person the bee often leaves the sting behind and so dies.
The life of a worker bee
Eggs are first laid by the queen bee. To hatch, the eggs need to be kept at a temperature of 73°–77°F. This temperature is maintained by the warmth of the bodies of young bees and of drones, or male bees, which constantly walk up and down the combs.
Three days after an egg is laid a larva hatches out of it. The larva is white without wings or legs.
The larva is fed with a very nourishing substance provided by the worker bees. It grows so quickly that in half a day it doubles its weight. The food consists of a kind of milk secreted by the pharyngeal gland of the worker bees.
The food becomes coarser after the third day and consists of a mixture of nectar and pollen, half digested by young worker bees before being fed to the larvae. On the ninth day the larva turns into a pupa and the cell in which it is lying is covered with an operculum or lid of porous wax.
Twenty-one days after the egg is laid the pupa develops into a fully formed bee complete with legs and wings. It emerges from the cell and soon begins to work.
For the first nine days of its life a bee stays at home and works inside the hive. For three days it cleans out the cells in preparation for the queen to lay eggs in them. During the next three days it feeds the older larvae with a mixture of pollen and nectar, and for the last three days it feeds the younger larvae with the substance secreted by its pharyngeal glands.
Between the tenth and twentieth days of its life a bee performs mixed duties. It stores in special cells the pollen brought by other bees to the hive; it builds the honeycombs, for it is during this period that the bee produces wax from glands in its abdomen; it makes its first trial or orientation flights; and it stands guard at the door of the hive.
From the twenty-first day of its life until its death the bee works outside gathering pollen and nectar which it brings home to feed the community. It ends its life by falling exhausted, too old and tired to struggle back to the hive.
How bees find their way home
Bees make long flights from the hive, constantly changing their direction, and one might suppose that they would get lost, but they have several methods of finding their way. Firstly, they recognize landmarks near the hive. If the hive is moved during their absence the bees will return to the place where it previously stood. They certainly guide themselves by the sun, and in addition their compound eyes are sensitive to the direction of what is called polarized light, which comes in definite directions from the sky seen when the sun is obscured. Our eyes have no ability to distinguish polarized from ordinary light, but experiments have shown that many insects can do this, and use the ability to guide themselves.
A method of signaling
Bees have a special gland situated at the end of the abdomen, which gives out a scent, imperceptible to humans but a sign of recognition among bees of the same family.
When young bees go in search of nectar for the first time the older bees stand in a line on the threshold of the hive. They buzz their wings and keep their abdomens turned upwards, at the same time squeezing scent from their glands. This hangs in the air and gives their inexperienced younger sisters a guide to the way home.