No. 3.] DAWSON — THE LOCUST INVASION. 127 



tivated, yet by persistent and combined effort much may be done 

 towards the protection of limited areas, by disturbing and har- 

 rassing the winged insects on their arrival in summer, and by 

 collecting and killing the eggs aud young brood in autumn and 

 spring. A great area of the western plains incapable of cultiva- 

 tion or use for other purposes than stock raising, must, however, 

 always remain as a breeding place for the locust, and it is only 

 by the application of some broad and general remedy, if such 

 can be found, that permanent amelioration can be effected. It 

 would seem possible by an organized system of supervision, 

 and the division of a large part of the prairie region into 

 blocks protected by rivers and other natural fire-guards, aud 

 by ploughed lines, to prevent the general spread of prairie 

 fires in the autumn, and afterwards to destroy the young locusts 

 by burning the grass off over those areas found to be tenanted 

 by them in spring. A similar course is urged by Dr. Studley 

 as worth trial. Mr. Mair informs me that it has been attempted 

 in the spring of 1875 near Portage La Prairie without effect; 

 but by choosing a time when the grass is dry, the wind moderate, 

 and the young insects pretty well advanced, it seems scarcely 

 possible that many should escape. Again, when winged swarms 

 are known to be moving on the province, making use of a 

 similar system of fire-guards, it would be possible to form by 

 preconcerted firing a strip of black country of great width, 

 altogether beyond its limits, over which it is improbable the 

 locusts wonld voluntarily attempt to pass. The extensive 

 planting of trees in all the cultivable districts, besides probably 

 effecting a climatic change causing increased damp and rainfall, 

 which would be unfavourable to the locust, would so break up 

 and divide the now uniform surface of the country as to prevent 

 the destruction of crops being so universal as it now sometimes 

 is. Coniferous trees, from the experience of Prince Albert Post, 

 seem specially worthy of attention.* 



It is my intention in a future paper, to summarize and discuss 

 the facts concerning the grasshopper visitation of 1875, with 

 especial reference to Manitoba and the North-west Territories, 

 and I shall be much indebted for any particulars which will 

 help me in this object. 



* This and other points will be found more fully treated in my 

 Report on the Geology and resources of the regions in the vicinity of 

 the 49th parallel, 1875. 



