CHAPTER XXII 



INSECTS ON THE FARM 



225. There are a great many kinds of insects found 

 on the farm, many of them useful, while a few kinds are 

 injurious because they feed on the plants and animals 

 of the farm. Not all the small animals are properly 

 called insects. Insects have just six legs, and their 

 bodies are made up of three parts that may be easily 

 distinguished: First, the head; second, the thorax, or 

 middle part; and third, the abdomen. The spiders, mites 

 and scorpions have eight legs. The common sow-bug 

 has twelve legs and is more closely related to the crabs 

 and craw-fish than to true insects. 



226. Changes of 

 Form in the Growth 

 of Insects. Nearly 

 all species of in- 

 sects have several 

 forms in passing 

 from the egg to the 

 mature insect. It 

 is like the stooy of 

 "The House that 

 Jack Built." The 

 female lays the 

 egg; the egg 

 hatches into the 



larva (caterpillar, Fig- 94> Sta es in the life history of the June- 

 , bug. After Howard Division of Entomology, 



grUD, Or maggOt) ; United States Department of Agriculture. 



(153) 



