SECTION XLVI. HOW INSECTS FEED 



How insects feed. Insect mouth-parts are fitted for 

 either biting or for sucking food. 



Insects have a number of parts to their jaws, and these 

 are so arranged that they work sidewise against each other. 

 The biting insects consume the entire substance of the 

 leaves, flowers, fruit, or wood on which they feed. This 

 is the reason that it is possible to kill such insects by 

 applying some poison to the plants on which they are 

 feeding. 



Some biting insects, however, feed in protected places 

 where it is impossible to reach their food with a poison 

 application. This is the case with the wood-boring in- 

 sects as a rule and with the cotton-boll weevil. Many of 

 the leaf-feeding insects, even, feed in the buds or some 

 other protected position that makes it hard to control them. 

 It is, therefore, necessary to know both the structure of 

 the mouth and something of the general feeding habits of 

 each insect before it can be destroyed. 



Different uses of biting mouth-parts. Among the bit- 

 ing insects the jaws are arranged in two principal positions, 

 either pointing downward toward the surface upon which 

 the insect rests, or forward, straight ahead of the insect. 

 These positions indicate a different use. When the jaws 

 point downward it means, as a rule, that the insect feeds 



253 



