26 The Destructive Locust of the West. (January, 
believe that we shall, after the lapse of years, be able to foretell 
with a good degree of certainty locust invasions, and be able to 
provide against the losses thus incurred. 
On the frontier of the Western States, in Colorado, or in the 
Territories of Wyoming, Montana, and Utah, where the losses 
from the ravages of the locust cannot easily be made up by im- 
portations from contiguous territories, it seems the most practica- 
ble mode to provide in years of plenty against years of want. 
We should imitate on a grand scale the usage of the ancient 
Egyptians under Pharaoh, who laid up in times of unusual har- 
vests stores of grain for times of famine. It is said that this has 
been done on a small scale by the Mormons. If this were done 
in the far West, in seasons immediately preceding insect years, 
which had been predicted by entomologists in conjunction with 
the meteorologists, we should be saved the distress, destitution, 
and even loss of life from starvation, which have resulted from 
ignorance of the laws regulating the appearance of destructive 
insects, especially the western locust. 
The Return Migration— By simultaneous observations for a 
number of years over the region liable to be visited by migratory 
hordes of locusts, added to the knowledge we already possess, it 
will not only be possible to predict the course of certain swarms 
from their breeding-places, and their probable destination, so 
that when a swarm starts from Montana or Wyoming, its arri- 
val in Colorado a week or a fortnight later may with some cer- 
tainty be predicted, and again, its arrival in Kansas and adjoin- 
ing States be announced witha certain amount of precision, as has 
already been done by Dr. Riley, but we shall be able to foretell 
the course taken in the return flight of their progeny in the suc- 
ceeding year. I will confess that previous to my visit to Kansas 
and Colorado, in 1875, I was skeptical as to Dr. Riley’s opinion 
that there was a general movement in a northwest course of the 
young of the previous year, broods from Missouri and adjoining 
regions northwestward. The facts and resulting theory have al- 
ready been stated in full by Dr. Riley and others. It remains 
to determine the causes of this return migration, this completion 
of the “ migration-cycle,” as Professor Dawson termsit. It is evi- 
dent that in this case the desire for food is not the cause, for food 
is many times more abundant in the Mississippi Valley than on 
the plains whither they return. The solution of the problem, I 
think, must be sought in the direction of the prevailing winds 
during the middle of June, the time when they become winged. 
