69 
Mountains. There were at least three great divisions of the migrants. 
One band went northeast through Hayden, as already recorded. A 
second took an easterly direction and proceeded as far as Eddy and 
Dunkley, a branch going northeasterly to within 5 miles of Steam- 
boat Springs. A third division reached the Williams Fork and fol- 
lowed its course In a westerly direction as far as Pagoda, at which 
place they were within 12 miles of the pomt where the former broods 
crossed the river at Hamilton. 
At Pagoda the number of insects was enormous. They were piled 
several inches deep in the road. The cliffs a mile away were seen, 
with the aid of the telescope, to be black with them. They fell into 
the ditches until these were almost choked with the dead. Those that 
crossed entered the oats and alfalfa. The former they ate to the 
ground and stripped the latter of leaves and tender shoots, leaving 
nothing but the bare stems standing for a distance of 30 or 40 feet from 
the margin. The coming of the insects was announced by telephone 
from 5 miles up the creek. one week before they reached this place, 
which was about the Fourth of July. It took the brood two weeks to 
pass a given point. 
At the time of our visit, August 9, the insects had retired to the 
hills, where they were found in great numbers in the act of egg-laying. 
CONCLUSIONS. 
To recapitulate, the insects are permanently located in the Danforth 
Hills. From this place immense swarms migrate in different direc- 
tions at times. The immigration is probably caused by overproduc- 
tion of the species. The ultimate destination of the swarm is deter- 
mined in no small measure by the number composing it. If a swarm 
succeeds in attaining a favorable locality, a brood may be produced 
which will cause another migration. The Wilhams River Mountains 
have more than once served as a temporary breeding ground. Each 
wave 1s followed by the enemies of the insect. These, combined with 
otherwise unfavorable conditions of the new country, would lead to 
its ultimate destruction. 
The insect has been here as far back as our knowledge goes, which 
is not very far, however. The ranchmen live far apart and the coun- 
try 1s altogether new. The advent of civilization has probably had 
httle influence on the destiny of the insect because the percentage of 
land under cultivation is very small and the localities where there are 
cultivated fields are only raided during the migratory stage of the 
insect’s life. Its normal home is not in the river bottoms, but on the 
dry hills. The only change that civilization has caused there is the 
substitution of the stock of the ranchman for the droves of elk and 
25524—No. 52—05 m———5 
