2 INSECTS INJURIOUS TO VEGETATION. 



nature, contribute to prevent the undue increase of the noxious 

 tribes. Too often, by an unwise interference with the plan of 

 Providence, we defeat the very measures contrived for our 

 protection. We not only suffer from our own carelessness, 

 but through ignorance fall into many mistakes. Civilization 

 and cultivation, in many cases, have destroyed the balance 

 originally existing between plants and insects, and between 

 the latter and other animals. Deprived of their natural food 

 by the removal of the forest-trees and shrubs, and the other 

 indigenous plants that once covered the soil, insects have now 

 no other resource than the cultivated plants that have taken 

 the place of the original vegetation. The destruction of insect- 

 eating animals, whether quadrupeds, birds, or reptiles, has 

 doubtless tended greatly to the increase of insects. Coloniza- 

 tion and commerce have, to some extent, introduced foreign 

 insects into countries where they were before unknown. It is 

 to such causes as these, that we are to attribute the unwelcome 

 appearance and the undue multiplication of many insects in 

 our cultivated grounds, and even in our store-houses and 

 dwellings. We have no reason to believe that any absolutely 

 new insects are generated or created from time to time. The 

 supposed new species, made known to us first by their un- 

 wonted depredations, may have come to us from other parts, 

 or may have been driven by the hand of improvement from 

 their native haunts, where heretofore the race had lived in 

 obscurity, and thus had escaped the notice of man. 



To understand the relations that insects bear to each other 

 and to other objects, and to learn how best to check the ravages 

 of the noxious tribes, we must make ourselves thoroughly 

 acquainted with the natural history of these animals. This 

 subject is particularly important to all persons who are inter- 

 ested in agricultural pursuits. For their use, chiefly, this 

 account of the principal insects that are injurious to vegetation 

 in New England, has been prepared. It has been thought best 

 to prefix thereto some remarks on the structure and classifica- 

 tion of insects, to serve as an introduction to the succeeding 

 chapters, and, in some measure, to supply the want of a more 

 general and complete work on this branch of natural history. 



