48 



The Rocky Mountain Locust. 



From the reports now received from Manitoba and various por- 

 tions of the Northwest Territory, and published in abstract with 

 these notes, it would appear that during the summer of 1875 two 

 distinct elements were concerned in the locust manifestation. 

 First, the insects hatching in the province of Manitoba and sur- 

 rounding regions, from eggs left by the western and northwestern 

 invading swarms of the previous autumn ; second, a distinct 

 foreign host, moving, for the most part, from south to north. The 

 locusts are known to have hatched in great numbers over almost the 

 entire area of Manitoba, and westward at least as far as Fort Ellice 

 on the Assiniboine river (long. 101° 20'), and may probably have 

 been produced, at least sporadically, in other portions of the cen- 

 tral regions of the plains ; though in the summer of 1874, this 

 district was nearly emptied to recruit the swarms devastating Mani- 

 toba and the Western States, and there appears to have been little 

 if any influx to supply their place. Still further west, on the 

 plains along the base of the Rocky Mountains, from the 49th 

 parallel to the Red Deer river, locusts are known to have hatched 

 in considerable numbers — but of these more anon. 



Hatching began in Manitoba and adjacent regions in favorable 

 localities as early as May 7th, but does not seem to have become 

 general till about the 15th of the month, and to have continued 

 during the latter part of May and till the 15th of June. * * * 



The destruction of crops by the growing insects, in all the 

 settled regions was very great, and in many districts well nigh 

 complete. The exodus of these broods began in the early part of 

 July, bat appears to have been most general during the middle and 

 latter part of that month, and first of August. The direction taken 

 on departure was, with very little exception, southeast or south. 

 It is to be remarked, that as there does not seem to have been dur- 

 ing this period any remarkable persistency of northwest or westerly 

 winds, the insects must have selected those favoring their intended 

 direction of migration, an instinct which has very generally been 

 observed elsewhere. 



* * * * * * * 



Foreign swarms from the south crossed the 49th parallel with a 

 wide front stretching from the 98th to the 108th meridian, and are 

 quite distinguishable from those produced in the country, from the 

 fact that many of them arrived before the latter were mature. 

 These nights constituted the extreme northern part of the army 

 returning northward and northwestward from the States ravaged in 

 the autumn of 1874. They appeared at Fort Ellice on the 13th 

 of June, and at Qu'Appelle Fort on the 17th of the same month, 

 favored much no doubt by the steady south and southeast winds, 

 which, according to the meteorological register at Winnipeg, pre- 

 vailed on the 12th of June and for about a week thereafter. After 

 their first appearance, however, their subsequent progress seems to 

 huve been comparatively slow, and their advancing border very 

 irregular in outline. They are said to have reached Swan Lake 

 House — the most northern point to which they are known to have 

 attained — about July 10th ; while Fort Pelly, further west, and 



