XIV 
PREFACE. 
Deer Lodge. They were also abundant at Virginia City and on Son 
Eiver and on the Upper Missouri between Helena and Fort Benton. 
They were also observed locally in the region south of Yellowstone Park. 
In Eastern Oregon swarms were observed between McDonnell's Ferry 
and Blue Mountains. He thus proved that the Rocky Mountain locust 
is indigenous over the immense region already mapped by the Commis- 
sion as the permanent breeding ground, and that the prospect for 1879 
was that local injuries would ensue in the Territories, but unless the 
spring and early summer were unusually favorable the Mississippi States 
would not be invaded. 
Mr. Thomas visited Colorado and other parts of the West, his special 
object being to ascertain if C. spretus would be found localized in Col- 
orado. He found this to be the case as far south as Colorado Springs, not 
only up in the canons and on the hills and mountains, but on the plains. 
He found them in considerable numbers in one or two canons, and show- 
ing a disposition to migrate. He found specimens on the very tops of 
the range, and on the very top of Pike's Peak. 
In Nebraska, Eastern Dakota, Minnesota, Manitoba, and Kansas no 
specimens, with one or two exceptions, were to be found, and their en- 
tire absence showed how completely they had left the Temporary Region, 
and the wisdom of the Commission in so designating the fertile country 
which, in exceptional years, suffers so greatly. 
There was one limited locality of a few acres in Southeast Nebraska 
where some hatched out. They were quite injurious around Bismarck, 
destroying the gardens, but they came in from the north. This erup- 
tion, which appeared late in Juty, was traced from British America to 
Kansas, and was confined to a narrow belt. It did not touch the west- 
ern border of Manitoba, or reach to the middle or interior of Dakota ; 
on the west it did not reach to Fort Benton, but was wholly east of that. 
It touched southern, but did not reach the extreme southeastern part of 
Dakota, passed south in the region of Ponca, Nebr., and thence south 
and southwest into Kansas. 
His investigations this year showed a strong tendency to rapid change 
in character of those locusts which remain for a few generations in the 
Sub-permanent Region. A few very limited flights were observed over 
the southwestern part of Minnesota. 
At the close of the year it was deemed unwise to publish a final report 
until further investigations had been pursued, and an appropriation of 
$15,000 for continuing them was therefore asked of Congress. The appro- 
priation was granted, but with it the Commission was charged with in- 
creased duties, and during the year now closing Mr. Riley's attention 
has been given to the subject of insects affecting the cotton-plant, while 
Messrs. Packard and Thomas have continued the locust investigation. 
Mr. Packard, with four students and one interpreter, visited portions of 
New Mexico and ascertained the southern portion of the range of the 
species with a view of more accurately mapping out the southern limit of 
