24 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



not been deemed necessary to confuse the ordinary reader by farther 

 definitions in this chai^ter, since it is the intention to give in a separate 

 memoir a synopsis of the genus, with descriptions of all the North Amer- 

 ican species at present known. 



In the second chapter we have given a chronological record of locust 

 injury in this country, which shows it to be no modern occurrence ; and 

 if the injury appears to have increased of late years it is only because 

 there is a larger cultivated area within the locust region, and the devas- 

 tation is more noticeable. The impression that this insect is on the in- 

 crease, and that its invasions are becoming more general and more fre- 

 quent is wide-spread, but it is scarcely justified by the facts, which 

 clearly indicate that the species has for ceuturies (and doubtless for 

 centuries of centuries) been at times excessively abundant and injurious 

 to the vegetation of the western plains. The history of 1877 is given 

 rather fully in this chapter, and is interesting in that it differs from that 

 of 1875, the year when the insects also hatched out in so large a part of 

 the temporary region. In that year the hatching was more uniform, the 

 young more vigorous, and, notwithstanding the spring and early sum- 

 mer were as wet and stormy as in 1877, the destruction of crops was 

 complete. In 1877, though the eggs were more numerous, the hatching 

 was more irregular, the young insects more feeble and diseased, and the 

 destruction, except in a few counties of lN"orth western Iowa and Minne- 

 sota, was trifling. The reasons for the difference in the two years are 

 sufQcieritly obvious. The winter of 1871-'75 was severe and steady- 

 more in keeping with the boreal country where the insect is at home — 

 and the eggs were well preserved and hatched more uniformly ; more- 

 over, they were laid by insects fresh from their northwest home. The 

 eggs laid in 1876 were largely from insects from the subpermanent coun- 

 try ', they were subjected to much mild and changeable winter weather, 

 while the spring raius were cold and disastrous to the young. In addi- 

 tion to these facts, the increase of natural enemies that inevitably fol- 

 lowed the few years of locust abundauce, and the greater efforts of the 

 farmer, and better means of fighting, should be taken into account. 



Chapter 3, in showing that the loss to the States between the Mis- 

 sissippi and the Eocky Mountains from this insect between 1873-'77 

 amounted to about $200,000,000, will serve to convey an idea to those 

 not conversant with the facts of the vast importance of the question 

 and the prominent role this tiny locust plays in the destiny of the 

 country. When we reflect that these losses fell most heavily upon a 

 iron tier population without wealth, we cease to wonder at the suffering 

 a:id consternation that at times prevailed, and must admire the courage 

 and fortitude with which the people have fought adversity. A means 

 of arriving at these losses from two wholly different stand-points, and 

 f. om entirely different data, has been employed, thereby rendering the 

 cue a check upon the other. 



Chapter 4 treats of the effect of locust injury upon the agricultural 



