Insects on the Farm 163 



two insects illustrate the difference of mouth parts as seen in insects. 

 Some, as the grasshopper, have biting mouth parts, while others, 

 as squash bugs, etc., have mouth parts suited to suck up the 

 plant juices or nectar, (a) Note the large eyes in the front and 

 side of the head of each insect. These are called compound eyes 

 because they are made up of a great number of simple eyes. (6) 

 Note also the feelers or antennae, and the mouth parts. The large 

 black jaws of the grasshopper are used for biting, while the long 

 coiled tongue-like organ of the butterfly is used for obtaining food 

 by sucking out the nectar from flowers. 



230b. The next region of the body behind the head is called the 

 thorax. In each insect the thorax is composed of three segments. Each 

 segment has a pair of legs attached. All insects have six legs, and 

 are sometimes called Hexapoda on this account. On each insect you 

 will usually find one or two pairs of wings. These wings are attached 

 to the second and third segments of the thorax. Notice that the 

 wings of the butterfly are covered with a "powder." This powder is 

 made up of small scales attached to the wing in rows overlapping 

 each other very much like the shingles of a roof. The wings of the 

 grasshopper are smooth and firm with a large number of small veins. 



230c. The next section of the body behind the thorax is called 

 the abdomen, which is made up of a number of segments or rings. 

 By looking along the side of the abdomen of the grasshopper there 

 will be seen a number of small openings or pores. These are the 

 breathing pores and nearly all insects have such breathing pores on 

 the abdomen and thorax. At the tip of the abdomen the segments 

 are changed a little in their form and size. This tip of the abdo- 

 men of the female is the egg depositor. The grasshoppers usually 

 bore down into the ground and deposit their eggs, while other in- 

 sects deposit their eggs in the bark of trees, young fruit, etc. 



230d. Collect some of the common insects from the plants in 

 the school-garden, or from the fields, and determine whether they 

 have sucking or biting mouth parts. 



231. General Method of Destroying Injurious Insects. 



The number of injurious insects appearing at any one 

 time is affected by their food supply, weather conditions, 

 and their natural enemies, such as birds, lizards, and 

 other kinds of insects. Wherever it is possible, encour- 



