BEES (Part 1 of 3)   Leave a comment

 

DEFINITION: any of a large super family (Apoidea) of broad-bodied, four-winged, hairy hymenopteran insects that gather pollen and nectar, have biting as well as sucking mouth parts, and often live in organized colonies; esp., the honeybee.

People have known ever since ancient times that the insects called bees make delicious honey from the nectar of flowers. There are more than 20,000 species of bees, and they are found all over the world except in Antarctica. Most people throughout the world recognize honeybees, and people in temperate regions know bumblebees as well (in some places they are called humble-bees). In Central America and South America many persons are familiar with tropical sting-less bees.

Physical Characteristics

Bees are flying insects that are related to wasps, hornets, and ants. Most bees have short, thick bodies covered with hair and, like all insects, six legs and three body parts: head, thorax, and abdomen. The thorax in turn has three segments, each with a pair of legs. A tiny waist connects the thorax and abdomen.

Ordinarily, most bees fly about 12 1/2 miles (20 kilometres) per hour, but they can fly much faster. They have two pairs of wings. One pair is attached to each of the last two segments of the thorax, but front and back wings are joined so that they may look like only one. The rapid movements of the wings make a humming sound in flight.

With three single eyes on top of their heads and two huge, helmet-like compound eyes, bees can see colour, pattern, and movement. The many facets of their compound eyes give them a total image in a mosaic of dots. Bees see all colours humans do except red, and they see ultraviolet, which humans cannot. Ultraviolet is often reflected by red flowers. Bees can also detect the polarization of light, which humans cannot. For example, in a blue sky polarized light forms a distinctive pattern around the sun, and even when the sun is behind the clouds bees can perceive that pattern and orient themselves to it.

Mandible, from Latin mandere, to chew; term applied to: (1) chewing jaws of insects and other arthropods; (2) the lower jawbone of mammals; (3) the upper or lower part of a bird’s beak.

Proboscis, snout, trunk, or other tubular organ projecting from the head of an animal.

On the lower part of their heads bees have biting jaws (mandibles) and a mouth-tongue proboscis, of several parts, which they use for sucking and lapping. Bees can distinguish very slight differences in sweet and bitter tastes, and they can also identify sour and salty tastes. Their front legs and feelers (antennae), as well as their proboscises are used for tasting. The antennae are primarily for sensing fragrances: bees find the perfumes of flowers even more enticing than their colours and shapes. Bees have no ears, but they can sense the vibrations of the surfaces upon which they alight.

The largest bees, which include some of the leaf cutter and carpenter varieties, may be up to about 1 1/2 inches (4 centimetres) long. Bumblebees are larger than most about 1 inch (2.5 centimetres) long. Honeybees range from about 1/2 inch to 1 inch (1.3 to 2.5 centimetres) long, depending upon the species. Some of the small leaf cutter bees are only 2/5 inch (1 centimetre) long, and sweat bees are 3/10 inch (0.7 centimetre) long. The tiniest species, the mosquito bees, may be only 3/50 inch (0.2 centimetre) long.

Most bees have black bodies, many with yellow or brown markings. Others have yellow, red, brown, and metallic green or blue bodies, some with brilliant metallic red or purple markings. Honeybees are dark brown with dark yellow stripes. Bumblebees are usually black with wide yellow or orange bands.

Food from Flowers

Honeycomb, a waxy many-celled structure made by bees for holding honey.

Depending upon its size and the length of its proboscis, a bee can enter many kinds of blossoms to sip nectar, the sweet liquid secreted by the flower’s glands. The bumblebee has a long proboscis and so is better equipped than many others for taking nectar from red clover, the flowers of which are made up of clusters of tubular blossoms. The nectar is carried in a special part of the bee’s stomach. During the digestive process enzymes are added, and the nectar becomes honey. Later it is regurgitated into the cells of the comb within the hive. When full, the cells are left until the honey has dried and thickened to the right consistency. Then the bees cap the cells with wax to preserve the honey and prevent further drying.

Pollen gathered from flowers clings to special branched or feathered hairs on the bee’s body. After pollen has accumulated, the bee brushes it off and moulds it into tiny balls mixed with honey from its mouth. This is beebread, the food of the young bees. The bee pushes these pellets into a particular formation of hairs or bristles for carrying them back to the nest. Honeybees have a pollen basket of stiff hairs on their hind legs. Leaf cutting bees have a dense brush on the underside of the abdomen.

Pollination

Fascinated by both colour and shape, bees show a strong preference for flowers with elaborate embellishments and respond eagerly to patterns of colour, particularly of yellow, blue, and ultraviolet. A more deeply shaded pattern is present near the centre of some blossoms. This clearly marked area acts as a carpet of colour to guide the bee to the nectar.

Snapdragon, herbaceous plants composing the genus Antirrhinum of the figwort family with showy white, yellow, pink, or red flowers; lower lip of large tubular corolla snaps shut if opened; many beautiful garden varieties have been derived from Antirrhinum majus.

The liplike petals of many flowers provide a place where a bee can land before entering. When a bumblebee alights on the lip of a snapdragon, the bumblebee’s weight, which is greater than that of most bees, opens the flower’s mouth, letting the bee enter the inner chamber to sip the nectar.

As bees go from one blossom to another, much of the pollen that clings to their bodies is transferred to the flowers of other plants of the same species, pollinating, or fertilizing, them. This permits the plants to produce their fruits and seeds. The bees’ greatest value by far is as pollinators of plants.

The Sting and Other Defences

A female bee has an egg-laying device (ovipositor) located at the end of its abdomen; the ovipositor also serves as a weapon and can inflict a painful sting. The bee’s sting has no food-capturing function. It has come to be used for defence against animals and humans that raid their honeycombs, and against robber bees and parasitic bees attempting to enter their nests.

Most bees can sting many times, but a honeybee worker has a tiny, hook-shaped barb that is caught inside the victim. This bee cannot fly away without tearing out its ovipositor and some internal organs a fatal injury. After the dying bee has flown away, its poison sac and the muscles left attached to the ovipositor keep pumping poison into the victim. As soon as possible the sting should be removed without squeezing the poison sac.

Africanised honeybees, also called killer bees, are particularly aggressive. They are descended from African bees that were imported into Brazil in 1956. The imported bees escaped in 1957 and began to mate with European honeybees the kind found in most hives. Although the sting of one Africanised bee is no more dangerous than that of a European honeybee, the Africanised bees release a chemical when they attack that signals other bees to come and join the attack. These bees may swarm over great distances in pursuit of a raider of their hives, and they have been known to attack in such numbers as to kill farm animals and humans. Since 1957 they have been moving steadily northward, and the first swarm entered the United States in October 1990.

Bumblebees sting when their nest is disturbed, but they are not easily aroused when they are gathering nectar. Sweat bees, attracted by perspiration, may alight on a person’s skin in summer. Their stings are sharp but not as painful as those of the honeybee.

Tropical sting-less bees defend their colony by crawling into the eyes, ears, and nose of an animal or under the clothing of a human raider. They bite, and create unpleasant sensations because of their sheer numbers. Some species secrete a caustic chemical that burns the skin.

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Posted 2012/02/15 by Stelios in Education

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