CHAPTER VII. 



THE PESTS OF CULTIVATED PLANTS. 



The great damage done to the crops grown both in the 

 home as well as in the commercial garden is caused by several 

 classes of pests. These pests, briefly stated, are: (1) insects, 

 (2) plant diseases, (3) physiological troubles, (4) predaceous 

 animals. 



Fig. 50. — Southern cabbage worm, showing complete metamorphosis, 

 a, adult; b, egg mass; d, larva or worm; «, cocoon. (Chittenden, United 

 States Department of Agriculture.) 



Few people realize the enormous loss due to these enemies, 

 chiefly because many growers are neither familiar with the 

 injury by the insects, nor do they see the small microscopic 

 parasitic plants which sap the vitality from the growing 

 host. The injury usually develops slowly, and when it is 

 discovered it is too late to remedy the damage. Many 

 people, who are close observers, know their plants are not 

 doing as well as they should, but they are not familiar enough 

 with the habits of the insects or appearance of the plant 

 diseases to correctly diagnose the trouble. 



