GOO REPORT UNITED STATES GEOLOGICAL SURVEY. 



lions. We, here, do not believe a word in the statements made from time to time that 

 the grasshoppers are dying, or that a parasite is eating them. We have seen tbem 

 eomo ont of water, mnd, and snow as strong as ever. They are " irou-elad." I wish 

 I were as sn re of one i)ropositi(m as I am that a machine will be invented that will 

 take them np from the ground and " leave not a wretch behind." 



Additional facts regarding the occurreuce of the locust (C spretus) 

 in Colorado and other Territories will be found in the following extracts 

 from an article in the Daily Inter-Ocean, Chicago, October 9, 1875, from 

 "the pen of Prof. Cyrus Thomas, State entomologist of Illinois: 



Tlieir hatehing-gronnd is known to extend over the vast area roughly designated by 

 Ihelollowing boundary-lines: On the east, the one hundred and thinl meridian; on 

 the south, the south line of Colorado and Utah ; on the west, the west line of Utah 

 extended north to British America ; the northern line being somewhere in British 

 America — even this area in the northern jiart being expanded indelinitely east and 

 west. Now for the proof. While connecte<l with the United States Geological Sur- 

 vey, under Dr. Ilayden, for four years, I traveled over a largo portion of this area, 

 traversing it on various lines east and west and north and south, studying somewhat 

 carefully the habits of these destructive locusts. During this time I noticed them in 

 the larva and pupa state, or depositing their eggs at the ibllowing ]daces : At vjirions 

 points along the enst base of and in the bordering valley of the mountains in Wyoming 

 and Colorado, from North Platte near Fort Laramie to the Arkansas River ; in Laramie 

 plains, and around Fort Bridger; from Utah Lake, in Utah, to Fort Hail in Snake 

 River V'alley, Idaho ; in Northwestern Dakota near the Red River of the North ; and 

 on both sides of the range in Montana along the valleys of Deer Lodge River, and the 

 branches of tlie Upper Missouri. I also obtained satistactory proof of the same thing 

 occurring in British America, uortli of Dakota ; in Middle Park, Colorado; and in the 

 regions west of that point; in Wind Rwer Valley, in Wyoming ; in Central Montana, 

 along the Yellowstone, and in the Green River country west of South Pass. These facts, 

 which are but a small portion of what might now be gathered, will give some idea of tlio 

 work necessary to bo done if we undertake to exterminate these insects by destroying 

 their eggs in their native haunts. It' it can bo shown, which is doubtful, that the 

 progenitors of theswarms which visit Kansasand Ntsbraska, after sweeping down from 

 the mountain regions, deposit their eggs within the limited area heretoiore mentioned 

 as the point of departure east, then, and then only, is it possible to devise a pieveut- 

 ive measure ap|)lieable to their nati\e haunts, as this, with the exception of a com- 

 paratively small region around the headquarters of the Missouri, is the only portion of 

 the broad plains lying along the east liank of the mountains susceptible of an exten- 

 sive system of irrigation. Before alluding to their operations in Kiinsas, Noljraska, 

 and other bordering States, I will ])resent some facts in regard to their migrations in 

 and frcmi the mountains and northern regions which will assist the reader in forming 

 a. more correct idea of their habits and the extent of their operations ; and here be it 

 remembered I coniine myself to the single species Calopteuiis fpretns. I have traced 

 a swarm from the area west of South Pa>s to their stopping-place and hatching ground 

 north of Fort Fetterman, from Northeastern Dakota nearly to Lake Winnipeg, and 

 have ascertained that some swarms have even extended their migrations, from some 

 supposed southwest i)oint, as far as the north side of this lake. It is also known that 

 in one instance, at least, those which left Colorado moved in the direction of Texas ; 

 those visiting Salt Lake Valley have reijcatedly come from the northeast, sometimes, 

 doubtless, from Cache and Bear River Valleys, and at others from the Snake River 

 region, while those hatched in Salt Lake regions moved south, in some instances re- 

 turning with the change of wind. In 18G4 those hatched east of the mountains in 

 Northern Wyoming and along the Yellowstone in Montana swept down the east Hank 

 of the range upon the fields of Colorado, while a part moved east to Manitoba and 

 Minnesota. In IdGT a swarm from the west side of the range poured into Middle 

 Park and there de[)osited their eggs, but those hatched from these faih'd to scale t heir 

 rocky bounds; yet, while these were vainly striving to have their mountain i)rison, 

 another horde from the barren regi(ms beyond s^veeping abiive them over the snowy 

 <Te8t, poured down upon the valleys east ; and in another instance a swarm was seen 

 passing for two days over Fort Hall from the southwest. On the other hand we fin<l 

 them extending their flight far into Texas in destructive hordes, yet New Mexico and 

 Arizona appear to be com])aratively free from them ; at least the very extensive collec- 

 tions made by Lieutenant Wheelei's expeditions in these Territories during the last 

 four years, which have been submitted to mp, contain but very few specimens of the 

 C. spirtits, and during my visit to New Mexico in ItfGD I found scarcely any specimens 

 south of iiaton Mountains, although comparatively abundant in Colorado, and even 

 in San Lnis Valley. I am therefore inclined to doubt the correctness ot the statement 

 niadt^ in reference to the grasshopper in these Territories in lc'55, if intended to apply 

 to this species. 



