1. Write down whether the following statements are true or false. Give extensive answers.

1. Mosquitoes appear in May.

2. The larvae feed on decaying animals.

3. The comma-shaped pupa is very small and inactive.

4. When after pupation the adult insects emerge, the transformation takes place on the leaves of the trees.

5. Among the blood-sucking mosquitoes only the males bite.

6. The ordinary, northern house mosquito holds its body parallel to the surface.

7. Both types lay eggs in hollow trees holding stagnant water.

8. The fly larvae live and develop in dustbins or manure.

2. Complete the sentences using the text and translate them into Russian.

1. They hurry … to deposit eggs.

2. The body is kept … .

3. … , and a mosquito breaks out.

4. … the slightest disturbance can lead to death.

5. They may be regarded as … .

6. Only the Malaria Mosquito … .

7. Before it pupates, … into the earth.

8. … is protected by … which is never cast.

9. The period … within one summer.

10. The greater … the spread of disease.

3. Answer the following questions on the text in written form.

1. Do all mosquitoes survive the winter?

2. Where do they live and breathe?

3. How do they breathe?

4. What does mosquito use until it dries and flies away?

5. What is a critical period in the mostquito’s life-cycle?

6. Are male or female mosquitoes vegetarian?

7. Why is it easy to distinguish the Malaria Mosquito from common gnats?

8. Malaria Mosquitoes should be destroyed. How can we do it?

9. Why is the House Fly dangerous?

10. How many flies can one female House Fly produce?

4. Translate a passage into Russian in written form. Text 20 honey-bee

Colonies

Many insects live together in communities or colonies which are supported by co-operative work. Bees, wasps, ants, and termites show this type of instinctive behavior. By practicing division of labour, they are better able to obtain an adequate food supply. Moreover, because they provide protection and favourable conditions for their eggs, these are more likely to develop into adults.

Bees live in beehives, in colonies, where they have a rigid caste system. There is one queen, which is bigger than the other members of the colony. Unlike other bees, she does not fly in search of nectar or pollen, but stays in the hive moving around the wax combs, laying eggs into the six-sided cells. She is the only female that is allowed to lay fertile eggs.

The bulk of the colony is made up of workers, which are also females but do not lay eggs because their reproductive organs are insufficiently developed (they are sterile). They do all the work in the beehive. They build combs, collect food, take care of the young grubs, and guard the hive against robber bees and other enemies.

Then there are the drones, which are all males and the largest bees in the colony (except the queen).

Their only duty is to fertilize the queen. They do not bring food, take care of the young grubs, or clean out the cells, etc.

Worker-bees

Worker-bees are capable of long flights sometimes going 1 km. or more from the hive in search of food. Like the drones and the queen, they have two pairs of membranous wings. Their mouth-parts have been modified to serve purposes other than taking food. The upper jaws (mandibles), which are shaped like little flattened spoons, are used to grind pollen and build cells. The lower mandibles together with the lower lip form a proboscis.

The bee flies from flower to flower sucking aromatic nectar. The nectar is taken into its mouth and moves to the honey-stomach, which is a storage crop. In the honey-stomach the nectar is mixed with saliva and changed into honey. When the bees return to the hive after their expeditions they place the honey in the open comb cells and allow it to undergo evaporation to remove large portions of water. When this is completed, the honey is used as a food supply for the whole colony.

Honey is also used by man. It contains a number of vitamins, is helpful to people suffering from emaciation, improves blood composition, and is very effective in the treatment of colds.

At the end of their abdomens the workers and the queen have stings’ which can be thrust out and withdrawn. The bee bends its body and drives in the sting, at the same time forcing a burning fluid into the flesh of the victim from a poison bag. When the bee attempts to withdraw the sting it is torn out of its abdomen which causes the bee's death.

Though a bee sting can be very painful, the poison contains medicinal properties and is used extensively in the treatment of rheumatism and other diseases.

Life-cycle

If you examine the wax combs you will see that the cells are of different sizes. The worker cells are the smallest, the drone cells are larger than those of the workers but smaller than the queen cells. The queen lays two kinds of eggs: out of one kind (unfertilized) hatch drones; out of the other (fertilized) -either queens or workers, according to the kind of cell in which the egg is laid and the food fed to the grub. The combs which are not occupied by eggs and larvae serve as food stores.

The eggs hatch into grubs (larvae) - white, wormlike, and legless. For the first few days all, without exception, are fed on a highly nutritious food called royal jelly, which is secreted from special glands by young worker-bees. Later the grubs, in the small and medium-sized cells, are fed only on honey and bee-bread, whereas the queen larva is given royal jelly. This grub grows faster, becomes much bigger than the other larvae, and is the first to pupate.

Distribution of Work

The duties of the bees within the colony depend on their age. A young worker-bee cleans out the cells. Then it is promoted to the position of a nurse, because it is better able to excrete the royal jelly than the older workers. Still later, when its wax-secreting glands mature, it is allowed to build combs. At this stage it also handles the honey, pollen, etc., delivered to the hive by the foragers, and clears away the scraps of refuse. Finally, it joins the food-gathering bees, and goes in search of nectar and pollen.

The building of combs is the most difficult part of the community's life. With their legs, bees remove little pieces of wax from the wax pockets, chew them with their jaws, make a foundation out of the mass that is formed, and cover it with one row of six-sided cells on both sides {back to back). This work is done by large groups of bees and consists of a chain strictly alternating processes, called reflex actions.

Nursing the young grubs, feeding them with royal jelly, collecting nectar and pollen, keeping the beehive in order - are also parts of a chain of reflex actions, alternating in a definite order.

Such chains of reflex actions which are interconnected and take place in a strict succession are called instincts.

Are Instincts Automatic?

The complex, seemingly purposeful and clever instincts of bees have given rise to the supposition that these insects can think. A convincing answer was provided by the experiments on wild Black Mason Bees, which were carried out in the middle of the last century by the French naturalist Fabre.

Black Mason Bees are large insects with dark-violet membranous rings and black velvety bodies. They do not make their cells in hives but on large pebbles, where they can get plenty of sunshine. The building material is clay and lime powder. The mixture, moistened with saliva, dries fast and forms very solid cell walls in which the larvae live.

Fabre found two pebbles, each carrying Black Mason Bees' cells, with the grubs in them due to emerge soon. He took two small sheets of grey paper and fixed one onto the cement walls of the cells on one of the pebbles. The other, curled into a cap, was placed around the second nest. In both cases the young bees had to cut their way out of the cells through a cement wall and a sheet of grey paper. But in the second there was a space between the cells and the paper.

Observations proved that the young bees emerging from the first nest did not mind the presence of a double wall. However, in the second case, having easily out through the hard cement barrier they did not even attempt to break through, the second, which was thin. And they all died, "lacking the slightest trace of intelligence", Fabre wrote.

This and many other experiments make it possible to assert that insects only seem to possess intellect or the power to reason. It is wrong to ascribe human reason to animals.

Pollination

Visiting one flower after another, bees ensure cross-pollination. This is even more important than producing honey or wax. Sometimes beehives are taken to the fields when honey-bearing plants begin to bloom.

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