Text 16

MAY-BEETLE

Habits

May-beetles appear in spring, in the month of May. During the day they hide among the leaves of trees, mostly birches and oaks.

May-beetles are vegetable-eaters.

Structure

The beetle's body consists of three clearly distinct parts - head, thorax, and abdomen. The head carries a pair of feelers (antennae), the eyes and the mouth-parts.

The thorax is composed of three segments and bears three pairs of legs and a pair of hard forewings which enclose the two membranous hindwings - the organs of flight.

On each side of the segmented abdomen are small openings, or spiracles, used for breathing. The body ends with the anus.

Locomotion

Beetles have three pairs of segmented (jointed) legs, growing out of the thorax. All insects re­lated to the May-beetle have these and are therefore classified as arthropods.

The two pairs of wings, the forewings, which are hard, and the membranous hindwings are also used as means of locomotion.

Orientation

Orientation in its natural environment is achieved by means of the nervous system and the organs of sense.

The eyes of the beetle are compound and made up of large number of separate units. Each unit can see only that part of the object that is directly opposite it. The objects are therefore perceived "piecemeal" and have to be "rebuilt" into one whole. The eyes are not big and can only distinguish things at short distances.

The feelers (antennae) serve as the organs of smell and enable beetles to scent food a considerable distance away. Having landed on a tree the beetle begins to run about the leaves touching them with the palps, segmented appendages to its mouth-parts, which serve as the organs of touch.

External Cover

The May-beetle differs from the worm and the mollusc in having a hard external cuticle. This is composed of a substance known as chitin, which is excreted by die skin cells. The cuticle serves as protective armour.

Where the segments join, the cuticle is thin and flexible, allowing the beetle to move its head, thorax, abdomen, legs, feelers and palps.

The cuticle is not only protective armour; it also serves as an exoskeleton, to which the muscles are attached.

Different sections of the beetle's skeleton and body, as well as the legs, are set into motion by muscular contraction.

Nutrition

The beetle takes a leaf between its legs which end in claws, and bites off a piece with its jaws.

The jaws, two hard, toothed plates, are found on each side of its mouth. The upper and lower lips hold the food, which is immediately swallowed. The beetle is unable to chew, therefore quite large pieces of leaves enter the intestine.

Tasks

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

1. The head carries a pair of antennae, the eyes, the mouth-parts and three pairs of segmented legs.

2. The two pairs of wings are used as means of locomotion.

3. The eyes of the May-beetle are small.

4. The external cuticle is always thin.

5. The external cover is composed of a substance known as chitin.

6. Having two toothed plates, the beetle is able to chew.

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

1. On each side of the segmented abdomen are … .

2. … by means of the nervous system and the organs of sense.

3. Having landed on a tree the beetle begins … .

4. … to more its head, thorax, abdomen, legs, feelers and palps.

5. The upper and lower lips hold the food … .

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

1. What is the body of the May-beetle composed of?

2. What organs are used by them for locomotion?

3. The eyes of the May-beetle are compound, aren’t they?

4. What aims do antennae serve?

5. What is the external cover of the May-beetle made up of?

6. How does the process of nutrition occur?

4. Translate a passage into Russian in written form.