CHAPTER VIII 

 INSECTS 



Insect Enemies. Almost every plant has an in- 

 sect enemy that feeds upon it; and the farmer who 

 wishes to protect his crops, orchards, and gardens 

 must know how to fight these plant enemies. In- 

 sects form about nine-tenths of all the animal life 

 upon the earth. Hundreds of millions of dollars* 

 worth of farmers' produce is lost each year because 

 of insects. (Figs. 38, 39, 40, 41, and 77.) 



Insect Friends. Certain insects, however, are use- 

 ful to mankind. Some gather honey and carry 

 pollen from flower to flower, while others spin silk, 

 and still others clean away dead animals. These 

 friends of man are: bees (Fig. 45), wasps, dragon 

 flies, tiger beetles, silkworms, and many others. 



Parts of Insects. Insects when full-grown have 

 the body divided into three parts: the head, the 

 middle part, or thorax, and the abdomen or back 

 part. On the head are the eyes, the feelers, called 

 antenncs, and the mouth. The chest or thorax bears 

 the wings, of which there are usually two pairs, and 

 six legs. 



Biting Insects. There are among insects two 

 kinds of mouths. Such insects as grasshoppers and 

 beetles bite the food. Others, such as mosquitoes, 

 bedbugs, bees, and butterflies, suck their food. 



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