any community may, by enlisting all the forces at its disposal, 

 effect a measurable saving of its crops, and that the evil, if it 

 could be confined to the locusts that hatch here, might be prac- 

 tically eradicated in a few years at most But there is a growing 

 apprehension in the minds of the people of Minnesota, brought 

 about mostly by a consideration of events occurring in our own 

 state only, and that too only within the last four years, that we 

 are more liable to locust invasions than other states; that the 

 locust evil may become a permanent one here even without rein- 

 forcements from abroad, and that its area may gradually extend 

 until it covers regions still unknown to it. This apprehension is 

 increased by the fact that the invasion of the present year has 

 reached, (to the south of St. Paul,) about one degree of longitude 

 further east than it has ever been known to extend before. It is 

 possible that Minnesota may, from its geographical position, 

 suffer from locust invasions more frequently in the long run of 

 fifty or a hundred years than Kansas or Manitoba, though a 

 history of the last twenty years shows no special preponderance 

 in favor of either state; it is possible that its cold climate, and 

 the high and dry soil of its southwestern counties may furnish a 

 a more congenial and permanent home to the swarms that breed 

 here, though the events of the last four years, when fairly con- 

 sidered, show that even here there is a constant decrease in the 

 numbers of such swarms as remain; and finally the history of the 

 whole Mississippi Valley shows that the Rocky Mountain Locust 

 is confined on the east by a tolerably well defined limit which up 

 to the present time, neither invading swarms, nor their progeny 

 have essentially altered. Upon all these points the Entomologists 

 are repeatedly called upon to express their opinions, which have 

 been freely and in most cases cautiously given; and these opinions- 

 are in turn repeatedly called into question by those who persist in 

 mistaking opinion for prophecy, or in applying a general rule to 

 a limited area, or to a particular year, But it is evident that there 

 is still room for the study of the physical character of the locust, 

 and of the geographical, geological, climatic or other causes by 

 which it is influenced. 



HISTORY OF PAST INVASIONS. 



Until within the last four years the migratory species of locusts 

 has been so infrequent and transient a visitor in Minnesota, that 

 the details of its former visits are almost forgotten. There is no 

 definite knowledge of any such visit down to the year 1855, unless 



