Insects on the Farm 161 



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 abdomen of the 

 female is the egg depositor. The grasshoppers usually bore down 

 into the ground and deposit their eggs, while other insects deposit 

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



230d. All insects are constructed very much alike, there being 

 slight differences in certain parts in the different kinds. Collect 

 some of the common insects from the plants in the school-garden. 





Fig. 101. This apple might have been kept sound by'spraying. 

 From Cornell University Junior Naturalist. 



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 is affected 

 by their food supply, weather conditions, and their nat- 

 ural insect enemies. Wherever it is possible, encour- 

 agement should be given to the natural enemies, some 

 of which will soon be mentioned. Sometimes they can 

 be killed by running heavy rollers over the fields, plow- 

 ing or harrowing. The leaf-eating forms can frequently 



