10 



other, and throughout all this area locusts were found to be hatch- 

 ing in 1874. On acquiring wings, these flew northward early in 

 July, and portions of them alighted in the range of counties next 

 beyond those they had already occupied, leaving vacant the ground 

 they had covered on hatching. By the 15th of July they had en- 

 tered Blue Earth, Nicollet, McLeod and Renville counties. By 

 the latter date, new swarms had begun to pour in from the north- 

 west, and passed over the western counties to the southward. That 

 these additional swarms did not add much to the stock of eggs de- 

 posited by our own broods is probable, for two or three reasons; 

 first, because their progress, so far as it could be traced, was en- 

 tirely across the state, and across most of western Iowa, before 

 laying eggs; and secondly, because the principal hatching-ground 

 of 1875 was precisely in those counties which had been already 

 occupied by our own stock in 1874 (before the arrival of new 

 comers) with some slight additions to the eastward. Eggs were- 

 also laid, later in the season, in scattered spots in some of the 

 northern counties, and in six towns in Meeker county, by swarms 

 coming in from the northwest about the first of August. But the 

 greater portion of the locusts hatched in 1875 were found along 

 the Minnesota River, and these on flying moved southward, and 

 alighted in the range of counties next beyond those they had just 

 occupied, where they remained and deposited eggs during July and 

 August. Of the swarms hatched from these last spring some flew 

 away to the southward early in July, while others flew northward, 

 some alighting along the Minnesota, and others moving still fur- 

 ther north. Other swarms also came from the west, from the Red 

 River valley, into several of the northern counties, and were prob- 

 ably a portion of those that hatched along the Red River. By the 

 10th of July all these had made their appearance in thirteen coun- 

 ties besides those in which they were hatched, but generally in 

 small and scattered bodies, and in only two or three towns in a 

 county; they were most numerous in Renville. Douglas, and Otter 

 Tail counties. 



The object of the preceding paragraph is to show that it is 

 probable that the locusts which hatched in Minnesota last Spring- 

 were to a considerable extent the descendants of the swarms 

 which entered the State in 1873. However unimportant it may 

 seem, it has a certain value if it enables us to judge of the effect 

 upon the Rocky Mountain locust resulting from a four years v 

 continuous breeding in our climate. 



