XVI 

 PLANT PESTS 



There is no part of a plant exempt from insect attack: 

 leaf, stem and root; bark, wood and pith; bud, flower and 

 fruit; all are eaten. 



There is no part of the growing season free from danger 

 of their depredations. Some come early, like the bud moth ; 

 some come late, like the fall webworm; some compass the 

 whole season by repeated broods, like the codling moth; 

 some persist through several seasons* like wireworms and 

 white grubs. 



They have all specialized more or less for feeding on par- 

 ticular kinds of plants. Some are general feeders but most of 

 them eat only of one kind of plant, such as the strawberry, 

 or of a few closely related plant species, such as cabbage and 

 kale, beets and spinach, tomato and tobacco, melon and 

 cucumber, peach and plum ; timothy and other grasses. 



1. Destroyers of herbage. — This is the most numerous class 

 of injurious insects. Green herbage is the most abundant sort 

 of food on earth, and insects are its greatest consumers. As 

 compared with the grazing beasts, they make up in numbers 

 what they lack in size. Grasshoppers and army worms and 

 the gipsy moth larvae browse like the beasts rather generally 

 on every green part above ground; but most herbivorous 

 insects confine themselves to one part, and feed in one par- 

 ticular way. There are all these classes of leaf-eating insects 

 that may be found side by side on a single tree: 



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