CHAPTER XXII 



REPRESENTATIVE INSECTS 



(By Vasco M. Tanner, Brigham Young Universitt) 



THE LOCUST 



The locust or grasshopper is one of the most common insects, 

 being known to practically all people, because very few boys and 

 girls grow up without having some experience with a grasshopper. 

 They are widely distributed throughout the world, living on grass 

 and low-growing plants of the fields and open country. In the 

 United States many destructive species are found. As early as 1743 

 Mr. Smith reported the damaging activities of Melanoplus atlanis 

 in the New England states, and from 1855 to 1877 many outbreaks 

 of grasshoppers were reported in the western United States. Even 

 today the national government is expending large sums annually 

 to keep down the activities of the many destructive species. 



The grasshopper is a typical insect, and along with the beetles 

 and bees, to be discussed later in this chapter, may serve to illus- 

 trate the general structure of the class Insecta. 



The insect body is divided into a series of rings, or segments, and 

 the segments are made up of hardened plates. These plates are 

 known as sclerites, and the depression between the plates is called a 

 suture. The hardness of the plates is due to the deposition of a horny 

 substance called ckitin. In many places two or more of these rings have 

 gro^\Ti together, or are fused. Again, in certain regions of the body, 

 parts of the segments may be lost. Eegardless of the amount of varia- 

 tion in this respect, we find that the segments are always grouped into 

 three regions, known as the head, thorax, and abdomen. 



The head is made up of a number of segments, which are fused 

 together, forming a boxlike structure known as the epicranium. 

 This boxlike piece which surrounds the eyes and forms the basis 

 of attachment for the movable parts of the head extends down the 

 front of the head, between the eyes, to the transverse suture, and 

 down the sides of the head to the base of the mouth parts. The 

 sides of the epicranium below the compound eyes are known as 

 the genae, or cheeks, while the front of the head between the eyes is 

 called the frons. 



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