CHAPTER XVII 



THE CLASSIFICATION OF INSECTS, AND INSECT 

 BENEFITS AND INJURIES 



Linnaeus, the first great classifier of animals, divided the 

 insects into seven orders based on the character of the wings. 

 In the order Aptera, or wingless insects, he placed all insects 

 lacking wings. But now we know that there are wingless 

 moths, wingless beetles, wingless flies, and so on, and that 

 these different kinds of insects ought not to be classified to- 

 gether simply because through degeneration from one cause 

 or another they have lost their wings. 



The two-winged insects with balancers in place of the hind 

 wings Linnaeus called Diptera, and this order still stands about 

 as he established it. All the four-winged insects with mem- 

 branous wings he placed in two orders, those having stings in 

 the Hymenoptera and those without stings in the Neuroptera. 

 Insects with their wings covered with scales he called Lepi- 

 doptera, and insects with their fore wings thickened he called 

 Coleoptera if the wings were thickened for their whole length, 

 and Hemiptera if their wings were thickened only over the 

 basal half. 



Although now different criteria are used as a basis for insect 

 classification and the class Insecta is divided into more than 

 seven orders, Linnaeus's seven ordinal names are still used, and 

 the insects indicated by each of them are largely also charac- 

 terized by the condition of wings indicated by the names. But 

 out of the Linnaean orders Aptera and Neuroptera, nine dif- 

 ferent new orders, beside the two still bearing the same 

 names, have been made. And three other new orders have 

 been made for insects taken from the Hemiptera and the 

 Coleoptera. In all we now recognize nineteen orders in the 

 class Insecta. This, at least, is the American practice. Most 



