INTEODTJCTION. 



ing the most damage to the horticulturist at the present day ; and 

 if we take into account the multitude of insects which are preying 

 upon our shade and ornamental trees and shrubs, which, in the 

 estimation of many, are scarcely inferior in value to the fruit bear- 

 ing trees, we may safely conclude that the prospect is very remote 

 when the work of the practical entomologist will cease or mate- 

 rially diminish. And the force of this view is greatly enhanced 

 by the occurance, every year, to a greater or lees extent, of new 

 species of noxious insects, or rather of insects which, having ex- 

 isted here or elsewhere in moderate numbers, from time imme- 

 morial, have suddenly sprung into destructive profusion in conse- 

 quence of an abundant supply of congenial food, or the absence of 

 their natural enemies, or other conditions favorable to hfe, some 

 of which are known, and some of which are obscure or inscrutable. 

 The Colorado Potato-beetle, the Currant Saw-fly, the Asparagus- 

 l)eetle, and the Bruchus granarius; to which we might add the 

 Pear-caterpillar {Callimorpha Lecontei), and the Lesser Apple- 

 leaf folder {Tortrix malimrana,) treated of in the following re- 

 port, were all unknown here as noxious insects until within the 

 last few years. It is true that some noxious insects, on the other 

 hand, have greatly diminished, and some, which have been the 

 sorest scourges of the orchardist, such for example, as the notori- 

 ous Bark-louse of the apple tree, seem to be in the process of ex- 

 tinction. But we must not draw too much encouragement from 

 this state of things, since it is also true that noxious insects are 

 sometimes known to disappear from one section of the country, 

 only to break forth in greater number and virulence in another. 

 The Chinch-bug, which at one time rendered the raising of spring 

 wheat an impossibility in Northern Illinois for several years in 

 succession, has, for many years, been wholly unknown in this seo- 

 tion. And yet this very year it has again made its appearance in 

 considerable profusion in a few localities, and I have recently 

 heard of its having been found hybernating under the sheaths of 

 corn-stalks in my own county of Kane ; not in great numbers, it 

 is true, but sufliciently numerous, I fear, to start a colony for the 

 succeeding year. 



"Whilst it is the budness of the scientific entomologist, in apply- 

 ing his knowledge to economic j^urposes, to test the value of the 

 various antidotes which have been recommended against our in- 



