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to the small acreage planted) they were in other places noticeably- 

 fewer than in former years. 



This continuous decrease in numbers has resulted from several 

 causes, and the first of these is the early stage of laying just al- 

 luded to, by means of which large numbers of locusts have hatched 

 out during the last two autumns, and have died without repro- 

 ducing themselves. In this connection, the state of Minnesota 

 has an advantage over more southerly regions, in the fact that we 

 are situated nearer to the breeding-grounds of invading swarms. 

 Of these the earlier comers are more likely to pass over us before 

 reaching the full period of their development, while the later 

 comers are cut off by our earlier frosts; and of the eggs which are 

 left with us, being deposited earlier in the season, more are likely 

 to hatch in the fall and become harmless. On the other hand, the 

 invaders are more likely to mass their forces in more southerly 

 states, reach them in full maturity, and remain later in the sea- 

 son, while the eggs, being deposited later than ours, remain mostly 

 unhatehed until spring. These considerations enable us to under- 

 stand why certain counties in Missouri, where the locust hatched 

 in 1875, presented in May such a picture of devastation and deso- 

 lation as Minnesota has never seen in all its locust experience. 



But while becoming prematurely developed, (if this is a correct 

 expression of the facts as stated,) the locust had also become 

 shorter lived. One year ago, there was hardly such a thing as a 

 Rocky Mountain locust to be found in Minnesota by the first of 

 September. The swarms that had hatched along the Minnesota 

 river in the spring, and had alighted but a few miles further to the 

 south in July, had almost totally perished in August, without 

 extending the territory of their occupation more than the width of 

 one county beyond the area which they covered on alighting. A nd 

 in this connection we owe more to the Tachina maggot than many 

 are willing to allow. But of the invading swarms of the present 

 year, though large numbers of the bodies of the dead could be 

 found in the fields early in September, (something unusual, from 

 the fact that heretofore they have hardly ever been found at all,) 

 large numbers remained alive until they were killed by frost, and 

 even then died with eggs unlaid. 



Still another effect of naturalization during the last four years 

 is an apparent change in character, slight in itself, but showing 

 what the tendency would be if the locust were to continue to breed 

 here. While it has lost some portion of its inclination or its ability 

 to migrate, it has also lost somewhat of its gregarious character. 

 This was shown by the young locusts last spring, moving over the 



