65 



Mountains. There were at least three great divisions of the migrants. 

 One band went northeast through Harden, as ah-eady 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 AVilliams Fork and fol- 

 lowed its course in a westerly direction as far as Pagoda, at which 

 place they were Avithin 12 miles of the point where the former broods 

 crossed the river at Hamilton. 



At Pagoda the number of insects Avas enormous. They Avere piled 

 several inches deep in the road. The cliU's a mile aAvay Avere seen, 

 AA'ith the aid of the telescope, to be black Avitli them. They fell into 

 the ditches until these Avere almost choked Avith the dead. Those that 

 crossed entered the oats and alfalfa. The former they ate to the 

 ground and stripped the latter of leaA^es 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 Avas announced by telephone 

 from 5 miles up the creek one Aveek l)efore they reached this place, 

 AA'hich Avas about the Fourth of Jul3^ It took the brood two Aveeks to 

 pass a giA^en point. , 



At the time of our A'isit, August 0, the insects had retired to the. 

 liills, Avhere they Avere found in great numbers in the act of egg-laying. 



CONCLUSIONS. 



To recapitulate, the insects are pei-manently located in the Danforth 

 Hills. From this place immense sAvarms migrate in different direc- 

 tions at times. The immigration is probably caused by OA^erproduc- 

 tion of the species. The ultimate destination of the SAvarm is deter- 

 mined in no small measure by the number composing it. If a sAA^arm 

 succeeds in attaining a faA^orable locality, a brood may be produced 

 Avhich will cause another migration. The Williams RiA'er Mountains 

 have more thali once serA'ed as a temporary breeding ground. Each 

 Avave is folloAA'ed by the enemies of the insect. These, combined Avith 

 otherAvise unfavorable conditions of the new country, AA'ould lead to 

 its ultimate destruction. 



The insect has been here as far back as our knoAvledge goes, Avhich 

 is not very far, hoAvcA^er. The ranchmen live far apart and the coim- 

 try is altogether new. The advent of civilization has probably had 

 little influence on the destiny of the insect because the percentage of 

 land under cultiA^ation is A'ery small and the localities Avhere 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 ciA'ilization has caused there is the 

 substitution of the stock of the ranchman for the droves of elk and 



25524— No. 52—05 m 5 



