
CAPABILITIES WITH REFERENCE TO SETTLEMENT. 307 
fortunately prevent its increase and continued abode in the eastern 
prairie region, appear to be chiefly climatic. It would seem that the 
locust requires to bring it to healthy maturity the dry warm climate of 
the higher plains. In the eastern colonies the young are sometimes 
hatched in considerable numbers by a mild autumn, and perish in the 
succeeding winter. A relapse of cold and damp weather after their 
hatching in the spring, causes the death of great numbers. The eastern 
brood is a weaker one, and is accordingly more subject to the attacks of 
disease, and parasites. Mr. Riley catalogues four of the latter.* The 
two first (Trombidium sericium, and Astoma gryllaria) are mites; the 
two latter (Tachina anonyma, and Sarcophaga carnaria) flies, the larve 
of which feed on the grasshopper and live within it. All these seem 
to have appeared in connection with the swarm of 1874, and their progeny 
of this spring, in Manitoba. The Trombidium or silky mite attacks the 
egg. The Astoma attaches itself to the mature insect, generally under 
the wings. 
724. The first appearance of the locusts in formidable numbers in 
the Red River Valley, seems to have been in the year 1818, six years 
after the foundation of Lord Selkirk’s colony. They then arrived on the 
wing in the last week of July, and destroyed nearly everything but the 
wheat crop, which partly escaped, being nearly ripe.t Eggs were depo- 
sited, and in the following spring, the wheat and all other crops were 
destroyed as fast as they appeared above ground. Eggs seem again to 
have been deposited in 1819, and in 1820 the crops are said once more to 
have suffered greatly. The next recorded incursion is that of 1857, from 
which it would seem that for 36 years the insect had not appeared. In 
1857, the crops are said to have been so far advanced as to escape great 
damage, but eggs were deposited, and in 1858 all the young grain was 
devoured. In 1864, they again appeared, and left their eggs, but neither 
the adults, nor the young of 1865 were sufficiently numerous or wide- 
spread to do much damage. In 1867, numerous swarms poured in, but 
did little injuty, the crops being too far advanced; their progeny in the 
ensuing Spring, however, devoured everything, causing a famine. They 
again appeared in 1869, the young in 1870 doing much harm. In 1872, 
fresh swarms arrived, but as usual, too late to do much damage to wheat. 
Eggs were left in abundance in the northern part of the Province, and in 
the following Spring the farmers over considerable districts did not sow. 
* Loc. cit. 
+ Alex. Ross. Quoted by Prof, Hind. Assiniboine and Saskatchewan Exploring Expedition, 
