Bees: Biology, Pollination & Importance - A Comprehensive Guide

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Introduction to Bee

Bee, a flying insect that feeds on pollen and nectar gathered from plant blossoms. Bees carry pollen (a yellow dust containing a flower's male germ cells) from blossom to blossom. This enables flowering plants to produce seeds. The insect distributes pollen while collecting a flower's nectar—the sweet fluid that is made into honey. Bees are found in most countries of the world. There are about 3,500 species in North America and at least 10,000 species worldwide.

Bees have a defensive organ called a stinger.

Some bees are social insects, living in colonies made up of many thousands of individuals, much the same as do ants, wasps, and termites. About 5 per cent of all the different kinds of bees are social. The remainder are solitary bees, living alone or in small family groups.

Interesting facts about beesFossil bees found trapped in amber probably lived 80 million years ago.The largest bee is Chalicodoma pluto, a mason bee about 1 1/2 inches (3.8 centimeters) long. The largest honey bee, called the giant honey bee, is about 3/4 inch (19 millimeters) long.Size of a bee colony. A strong, healthy colony may contain between 50,000 and 60,000 bees.The smallest bee is Trigona minima, a stingless bee only 1/12 inch (2 millimeters) long. The dwarf bee, the smallest honey bee, is under 1/2 inch (13 millimeters).Speed. Worker bees fly about 15 miles (24 kilometers) per hour.Taste. Honey bees can identify a flavor as sweet, sour, salty, or bitter.A worker honey bee collects enough nectar in its lifetime to make about 1/10 pound (45 grams) of honey.

The Body of the Bee

Bees vary greatly in size. Some tropical social bees are only one-twelfth of an inch (2 mm) long. Others, such as the leaf-cutter bee, a solitary bee, sometimes reach a length of 1 1/2 inches (38 mm).

A bee's body, like that of other insects, is divided into three segments: the head; the chest, or thorax; and the abdomen. The insect has two pairs of wings and three pairs of legs.

Some bees have a defensive organ called a stinger, which is a modified ovipositor (egglaying organ). The stinger is usually a barbed shaft at the end of the abdomen. At its base is a gland that secretes poison. When the stinger is stuck into the skin of an animal, poison is pumped into the victim. When the bee attempts to pull away, the stinger is torn from its body and the bee dies. Bumblebees, however, have a barbless stinger and can sting repeatedly. Bees generally will not sting unless they are irritated or threatened. For most humans and animals, a bee sting is painful but not dangerous. However, some persons are allergic to the poison and require immediate injections of antihistamines when stung.

The bee's head, thorax, and legs are covered with fine hair. When the bee brushes up against a flower, pollen collects on the hairs. The lower legs are covered with rows of bristles called combs. By moving the combs over the pollen-covered hairs, the bee brushes the pollen off into pollen baskets—formations of longer hairs on the hind legs. Pollen accumulates on the hind legs in large clumps. It is then brought to the hive. Pollen is the bee's main source of protein.

The bee's mouth parts include scissorlike jaws and a long, tube-shaped tongue for sucking nectar from flowers. Nectar is stored in a special stomach called the crop. Two enzymes in the crop change the nectar into a sugary fluid. The sugary fluid is regurgitated and later turns into honey. Nectar is the bee's main source of carbohydrates. Glands in the abdomen produce a liquid that hardens into beeswax, a substance, as explained later, that is used to build the honeycomb.

Growth and Development

Bees, like most insects, become adults only after a period of growth and development called a metamorphosis. The insect emerges from the egg as a wormlike grub, called a larva. After completing its growth, the larva becomes a pupa, passing into an inactive stage during which the physical structures of the adult bee develop.

Social Bees

Colonies are divided into three social classes, or castes: queens, drones, and workers. Each colony contains a single queen—a sexually mature female whose function is to lay eggs. She is ordinarily the mother of the whole colony. Drones are male bees, produced to provide mates for new queens. A colony of 60,000 bees generally contains only a few hundred drones. Workers are sexually immature females. They are the most numerous bees in the hive, and are responsible for collecting food, caring for the young, and building the honeycomb.

After mating, the queen stores sperm in a pouch in her body. She releases sperm periodically during egg-laying. Eggs that come into contact with the sperm, and are thus fertilized, develop into females; eggs that are not fertilized develop into males. The queen usually stores enough sperm to last her lifetime (two to five years).

A worker develops from a female larva fed mainly on beebread, a mixture of pollen and honey. A queen will develop from a female larva fed only on royal jelly, which is secreted by glands in the head of an adult worker.

The two major types of social bees are the honeybee and the bumblebee.

The Honeybee

The most important bee, in an economic sense, is the honeybee. Its honey is used as a sweetener in syrups, candies, medicines, and pastries. The beeswax produced by the honeybee is used to make candles, floor waxes, lipsticks, polishes, and ointments.

The honeybee is also important because it pollinates crops. Many farmers and fruit growers rent hives of honeybees during the flowering season to improve pollination.

The honeybee colony, unlike that of most bees, lasts through the winter. The bees live on honey stored during summer. In the winter, the bees form a tight cluster around the eggs to keep them warm.

Honeybees are subject to a disease called foulbrood, caused by spore-forming bacteria. It can be controlled by the use of antibiotics.

Honeybees are not native to North America, but were imported from Europe in the 17th century. The Italian honeybee, a gentle bee originally from Italy, is the most widely raised variety in the United States. Other varieties include the Caucasian from the Caucasus Mountains, the Carniolan from Austria, and the German.

In 1956, an African variety of honeybee was introduced into Brazil to bolster that country's honey production. The African honeybees spread and crossbred with established European varieties. The result was a bee popularly called the "killer bee" because of its aggressive nature; such bees are quicker to attack than other bees and attack in very large numbers. "Killer bees" crossbreed with European varieties, producing aggressive offspring. "Killer bees" have expanded their range northward, reaching Mexico in 1986 and the United States in 1990.

The Queen and Drones

The queen is slightly longer than the other bees. She has a smooth, curved stinger used only in battles with rival queens. A queen sometimes lives four or five years, during which all her time is devoted to producing eggs. In summer she lays about one egg a minute.

A drone emerges from its brood cell 24 days after the egg is laid. Drones are shorter than the queen but are more robust. They have no stingers and do no work. After the mating season, they are usually driven from the nest or killed by the workers.

The Workers

Worker bees live only six weeks to two months. However, those born in the late fall may live through the winter, because they are free from the heavy burden of gathering nectar and pollen.

Workers collect beeswax secreted by their bodies and from it build small six-sided cells for storing honey and pollen and to serve as brood cells for eggs, larvae, and pupae. These cells are joined together to form the honeycomb. Brood cells for male eggs are larger than those for worker eggs. A cell for a young queen is larger still, made by tearing down the walls of several adjoining cells.

A worker's metamorphosis is completed in about 21 days. A young worker's first duties are to remove waste from the cells and to feed larvae still developing in other cells. Later, the worker guards the entrance of the hive and circulates the air inside by fanning its wings. After two or three weeks, the worker begins gathering nectar and pollen. It is estimated that a group of bees makes 20,000 to 40,000 separate trips in collecting enough nectar for one pound (454 g) of honey. In a year, a single colony may produce as much as 500 pounds (227 kg) of honey.

Workers communicate with each other primarily by performing a dance inside the hive. The dance causes air movements, which other bees detect. By dancing in various patterns, a bee can inform the other workers of the direction and distance from the hive of a food source and indicate its richness.

Three bees from the colony: worker, queen, and drone.What Is So Sweet About Honey Bees?

Honey bees visit as many as 1,000 flowers a day. They use their long tongues to sip nectar from the flowers. They store this nectar in their honey stomachs. The honey stomach is a special organ that breaks down the sugar in the nectar. When the bees return to the hive, they spit up the nectar. They give some of the nectar to other bees. The rest, they put into empty cells. That is where the nectar turns into sweet honey.

When a honey bee buzzes from flower to flower, it collects more than just nectar. Pollen sticks to its hairy body and hind legs. The bee brushes this pollen into “baskets,” or sacs, on its hind legs. Later, when the bee returns to the hive, it kicks off the pollen into cells in the hive. Honey bees use this pollen as food.

Why Do Honey Bees Dance?

Honey bees dance to tell other bees where the food is. Some honey bee workers are scouts. They fly around looking for flowers full of nectar or pollen. When they find these flowers, they hurry to the hive with the news.

At the hive, honey bee scouts dance in a figure-eight pattern. As they dance, they make a line between the two loops of the figure eight. If the line points straight up the hive, then the flowers are located in the direction of the sun. A line pointing to the right means that the flowers are to the right of the sun. The line points left if the flowers are on the left of the sun. The faster the bees waggle their tails while they dance, the closer the flowers are.

Worker bees in the hive want to know all about the nectar that was found. They often tap the scout bees to signal for a sample. The scout bee then spits up some of the nectar for the worker bees to taste. If the worker bees like the sample, they all fly off to the flowers.

Mating

When a hive becomes overcrowded, the workers develop a new queen by providing a female larva with a diet of royal jelly. A queen matures in about 16 days. If several new queens mature at the same time, they battle among themselves with their stingers until only one remains alive.

The new queen then begins her mating flight. She leaves the hive and attracts drones by secreting a pheromone, a hormone with a distinct odor. The queen outdistances all but the strongest drone, who becomes her mate while in flight. The drone dies immediately, and the queen returns to her hive to begin laying eggs, surrounded by worker bees who watch over her and feed her.

Establishing A New Colony

When a new queen develops, the old queen, accompanied by about half the workers, leaves the hive to start a new colony. The bees fly in a dense formation, called a swarm, centering about the queen.

As soon as the swarm enters the new hive, food is gathered and a new honeycomb is built. The workers secrete wax from glands on their abdomens and mold it with their mouths and feet to form combs. The queen deposits her eggs in these combs.

Beekeeping

A beekeeping establishment is called an apiary. Each colony within an apiary lives in its own hive. Formerly, bees were kept in cone-shaped hives, called skeps. To remove the honey, the whole colony had to be destroyed. A modern hive is generally a tightly closed box with a small entrance for the bees. The box contains vertical frames, any one of which can be taken out without disturbing the others.

The frames have an artificial wax foundation on which the bees build honeycombs. Brood cells are built on frames in the lower part of the hive, the brood chamber. In the upper section, called the super, the bees store their honey. A screen prevents the queen bee from entering the super to lay eggs, but allows the workers, who are smaller, to enter and fill the cells with honey. This upper section provides the honey for commercial use; the combs, when cleared of honey, provide beeswax. A machine called a honey extractor is used to remove honey from the combs.

Before disturbing a hive, a beekeeper blows smoke into it with a device called a smoker. The smoke quiets the worker bees and makes them much less likely to sting. The bees are then removed from the supers by a device similar to a vacuum cleaner.

Honey varies in taste and color according to the flowers from which the nectar is gathered. White clover, alfalfa, buckwheat, and fruit trees are good sources of nectar, and beehives are often kept in orchards.

Beekeeping is an ancient business. Until sugar became generally available in the 16th century, honey was the principal sweetener used in foods. Various places have been known in history for the production of honey. In the Bible, the Promised Land of the Israelites was called "a land flowing with milk and honey." Ancient Greece and Sicily were also important centers of honey production.

Bumblebees

There are many species of bumblebees found throughout the world. Bumblebees are the only social bees native to North America. A bumblebee is about one inch (2.5 cm) long, and is yellow with black stripes along the back. Bumblebee colonies do not survive the winter. The queen hibernates in her burrow, but the rest of the colony dies. A queen usually lives about five years.

Bumblebees are important plant pollinators.

In the spring, the queen selects a nest site, usually a clump of dry grass on the ground. Her body produces wax, which is secreted in thin scales through glands on her abdomen. With her mandibles, the queen uses the wax to build a honey pot, a small container for stores of nectar and pollen. She also uses the wax to build a brood cell, a six-sided structure in which she deposits a ball of pollen. She then lays 6 to 12 eggs on top of the pollen and covers the cell with a wax top. In a few days, the larvae emerge from the eggs and feed on the pollen. After metamorphosis, they become workers. The workers use their mandibles to cut away the wax top and emerge from the cell. They take over the work of gathering food and building new cells for honey and eggs.

The queen then devotes herself entirely to laying eggs. Late in the season, a few larvae develop into new queens. At the same time, a few drones are produced to mate with the queens and carry on the annual cycle.

Bumblebees are of great importance in plant pollination. They are the only bees whose tongues are long enough to reach the nectar of red clover blossoms and are needed to pollinate this important plant. The honey produced by bumblebees has an unpleasant flavor.

What Do Bumble Bees Drink?

Bumble bees, like other bees and wasps, sip nectar. Nectar is that sweet liquid made by flowering plants. Bumble bees have long tongues that can reach deep into flowers of red clover, vetch, and honeysuckle.

While the bumble bees drink the nectar, they also gather pollen from the plants. As they fly from flower to flower, some of the pollen falls off the bees and back onto the plants. This pollinates, or fertilizes, the plants so that they can produce seeds and spread. This, in turn, makes farmers very happy. They use these plants to feed their livestock.

Solitary Bees

There is no worker class among solitary bees, but only fully developed males and females. Each female builds a nest in a protected place. Although many nests may be found close together each female solitary bee provides for her own young and gathers her own food. Like all wild bees, solitary bees are chiefly valuable as pollinators of plants.

Carpenter Bees

The black carpenter bee has purplish wings and uses its strong jaws to bore a tunnel in solid wood. At the end of the tunnel, the female stores a supply of food and lays an egg. She then seals off the cell with chewed bits of wood stuck together with a glue-like secretion from her mouth. She repeats this process until the tunnel is filled with cells, each containing an egg and a supply of food for the larva. The little carpenter bee digs its nest in the pithy parts of twigs and small branches.

The carpenter bee uses its strong jaws to bore tunnels in solid wood.Miner Bees

tunnel in the ground. In the spring, a single female raises a family. Young females then help enlarge the tunnel, and each digs a separate compartment, branching off from the main tunnel, for her own eggs.

The mining bee tunnels into loose ground to make its home.Cuckoo Bees

do not build their own nests but lay their eggs in nests of other bees. Some cuckoo bees resemble bumblebees; they lay their eggs in bumblebee nests and their young are raised by bumblebee workers.

Leaf-cutter Bees

tunnel into wood, under stones, into trees and plants, or between shingles. The female cuts pieces of leaves, using them to build thimble-shaped compartments inside the tunnel. Each compartment contains an egg and a supply of food.

The leafcutting bee nests in cells made of small pieces of leaf.Mason Bees

use moist clay, mixed with sticks and leaves, to make their brood cells. The cells are sometimes built into holes in old walls, although the insects also tunnel into woodwork.

The mason bee uses moist clay, sticks and leaves to make its brood cells.

Bees belong to the order Hymenoptera. The honeybee (Apis mellifera), bumblebees (genus Bombus), and cuckoo bees of the genus Psithyrus belong to the family Apidae. Carpenter bees (genera Xylocopa and Ceratina) and cuckoo bees of the genera Melecta and Nomada belong to the family Anthophoridae. Miner bees (genus Andrena) belong to the family Andrenidae. Leaf-cutter bees (various genera) and mason bees (genus Osmia) belong to the family Megachilidae.