212 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



CHAPTER VIIL 



HABITS AND NATUEAL HISTOET. 



Kumerous original observations on the habits and natural history, on 

 the transformations and on the enemies of the Eocky Mountain locust, 

 have been recorded in Mr. Eiley's last three entomological reports to the 

 State of Missouri, in our second bulletin, which was largely prepared 

 therefrom, and in his "Locust Plague in the IJnited States," as well as 

 in other jjublications. In this and some of the succeeding chapters we 

 shall have frequent occasion to use these facts, and prefer to do so as 

 far as possible in the language in which they were originally recorded 5 

 but to avoid repeated reference to the same works, we shall simply 

 use quotation marks, and the reader will understand that where other 

 authority is not given, passages in quotation marks are from said wri- 

 tings. We do this the more readily that the' Missouri reports are with 

 difficulty obtained, and have had but a very limited circulation outside 

 the State. 



In treating of the habits of this insect we must needs do so from our 

 own as well as the general experience 5 and since this has been almost 

 entirely in the Mississippi Yalley, the facts and generalizations that 

 follow should be understood as applying more particularly to this region. 

 We shall also have frequent occasion to use the terms Permanent, Suh- 

 permanenty and Temporary regions, that have already been explained (pp. 

 131-6), and are set forth in map 1. In treating of the habits and natural 

 history of this insect, one thing has more particularly impressed us, viz, 

 the difficulty of making absolute statements that will cover all seasons 

 and all localities. The insect is so variable in its habits, and the con- 

 ditions of climate and plant-growth are so different in different parts of 

 the country affected, that what applies in one year or to one section will 

 not apply in all years or to all sections. Hence the necessity of the 

 regional classification just referred to, and the difficulty of laying down 

 rules that have not exceptions. 



DESTRUCTIVE POVTER OP LOCUSTS. 



^o one who has not witnessed the ravaging power of locusts can fully 

 conceive of or appreciate it. The organization and habit of the typical 

 locust admirably fit it for ravenous work. Muscular, gregarious, with 

 powerful jaws, and ample digestive and reproductive systems; strong 

 of wing and assisted in flight by numerous air-sacs that buoy — all these 

 traits conspire to make it the terrible engine of destruction which history 

 shows it to have been under conditions favorable to its excessive mul- 

 tiplication. Insignificant individually but mighty collectively, locusts 



