INSECTS 



ling moth, survive as larvae; those like the cabbage butter- 

 fly, as pupae; those like the potato beetle, as adults; others, 

 like the corn-root aphids, survive by some special means. 



Insect life and insect control. Having considered why 

 insects are able to cause so much damage to crops, we 

 need now to consider some 

 facts of insect life which may 

 help us to control this dam- 

 age. Two facts are espe- 

 cially important : first, insects 

 pass through definite stages 

 of development; second, the 

 way in which insects get 

 food. Since both have a 

 practical bearing upon insect 

 control it will be of interest 

 to notice each in detail, and 

 to illustrate the application 

 of this knowledge. 



Life history of insects. - 

 Most insects as the cabbage 

 butterfly, housefly, May 



Life history of May Beetle, 

 a. Adult. b. Egg. 

 c. Larva. d. Pupa. 

 e. Plant showing grub destroying 



beetle, etc., pass through four 



stages in their life-history- roots . p upa in burrow> (Han man: 



Missouri Agricultural Experiment 

 Station.) 



that is, from egg to adult. 

 The first stage is the egg; 

 second, larva or active stage; third, pupa or resting stage; 

 fourth, adult or mature stage. Some insects, like the grass- 

 hopper, make a short cut from egg to adult, omitting the 

 larval and pupal stages. The young of such insects are 

 much like the adult except in size and development of parts, 

 particularly the wings. They are called nymphs. 



