Chronological History 



53 



to the west of that province, it is more than probable that 

 the principal source of the 1876 invasion was Montana 

 and the Saskatchawan and Swan River countries. The 

 question as to how far the Northwest breeding grounds are 

 recruited, by the insects which hatch in the more fertile 

 country which I have designated as outside the species' 

 natural habitat, is a most interesting one ; for if thus 

 recruited, there is all the greater incentive for us to exter- 

 minate the young insects which hatch with us. All such 

 questions can be settled, if at all, only by a thorough 

 study of the subject by a properly constituted commission, 

 such as that now charged with the work, under the Depart- 

 ment of the Interior. 



EASTERN LIJSTE REACHED. 



A study of the eastern limit of the invasion of 1876, 

 compared with that of 1874, shows that it is peculiar in 

 reaching farther east in Minnesota and Iowa, and farther 

 south and east in Texas. The limit-line — extending from 

 Clay county, Minnesota ; bulging toward St. Paul, reach- 

 ing southwardly to the center of Iowa; thence westwardly 

 receding to Lawrence, Kansas, and bulging again to South- 

 'west Missouri — is more irregular between the 36th and 

 46th parallels than it was in 1874. On an average, how- 

 ever, it does not extend east of the 94th meridian. 



THE OMAHA CONFERENCE. 



As an incident of the 1876 invasion, the Conference of 

 the Executives of those States and Territories which most 

 suffer from locust ravages, and of scientific gentlemen 

 interested in the subject, held at Omaha, Neb., on the 

 25th and 26th of October, is worthy of mention. The 

 following gentlemen, with the writer, were in attendance: 

 Prof. Cyrus Thomas, of Illinois; Gov. Sam'l J. Kirkwood, 



