THE AMERICAN ENTOMOLOGIST. 



75 



tliey laid any eggs, so far as could be seen at the 

 time or ascertained from subsequent observa- 

 tions. Tlieir next lighting place was in Du- 

 buque county, Iowa, seven miles to the north- 

 west of Soulard's farm. There they stripjied the 

 woods of their foliage to about the same extent, 

 and disappeared in the same hurried manner. 

 Although there is no direct proof of the identity 

 of tliis insect with the Hateful Grasshopper, yet 

 it is difficult to refer it satisfactorily to any other 

 species. None of the Grasshoppers indigenous 

 to Iowa, Wisconsin, and Illinois, are physically 

 capable of tlying great distances through the air, 

 and the only other insect that ever preys in 

 large swarms upon the leaves of trees in that 

 region is tlie common Maj'-bug (Lachnvsterna 

 quercina. Knoch), which occurs in May and 

 June, and not in July and August. 



The above facts, and others which it would be 

 tedious to particularize, sufficiently show that 

 the Hateful Grasshopper, when suddenly trans- 

 ferred from its native alpine home in the llocky 

 Mountains, some eight thousand feet above the 

 level of the sea, to the warm regions of the val- 

 ley of the Mississippi, less than a thousand feet 

 above the sea level, gradually becomes diseased, 

 and barren, and loses more or less its natural 

 appetites and instincts. Why we do not observe 

 the same phenomena in the case of the Colorado 

 Potato-bug, which was originally a denizen of 

 the same cold, alpine country, is not difficult to 

 explain. The former insect reaches the Missis- 

 sippi lowlands at one sudden flight, and in one 

 season; it has therefore no opportunity to be- 

 come gradually acclimatized and inured to the 

 new "conditions of life" under which it is called 

 upon to exist. Consequently, it becomes dis- 

 eased and barren, and finally perishes. The 

 latter insect, on the other hand, has reached the 

 Mississippi lowlands only by slow and gradual 

 approaches, breeding at every way-station on 

 the road, and thus becoming — generation after 

 generation — more and more acclimatized to a 

 higher temperature, as indicated by the thermo- 

 meter, and to a greater atmospheric pressui'e, as 

 indicated by the barometer. Consequently, it 

 may now be considered as a permanently accli- 

 matized resident of our great Western valley; 

 though even here it thrives much better, and ex- 

 tends eastward much faster, in a cold northerly 

 than in a warm southerly latitude. If the good 

 people of Missouri and Illinois are particularly 

 anxious that the Colorado Grasshopper should, 

 like the Colorado Potato-bug, be permanently 

 colonized among them, we think that this might 

 probably be eft'ected by gradually acclimatizing 

 the insect at various points along the road that 



leads from Colorado to these States. But, as 

 this would be a very slow, expensive, and labo- 

 rious process, we do not intend to try the experi- 

 ment, until a few thousand dollars have been 

 appropriated for this express object by the 

 legislatures of those two great and enterjjrising 

 iStates. 



"But,'" it may be objected, "allowing that 

 the Colorado Grasshopper cannot breed in the 

 ISIississippi valley, what security have we that, 

 at some future time, it may not fly all the way 

 from the Rocky Mountains to the eastern bor- 

 ders of Missouri and Iowa?" We answer, that 

 we have traced back the history of this insect as 

 far as the year 1820; that in all these forty-eight 

 years, although no less than seven invasions of 

 the country to the east of the Rocky Mountains 

 have taken place, namely in 1820, 18.56*, 1857t, 

 ISCiit, 18G6, 1867, and 18G8, it has never yet got 

 within 112 miles of the Mississippi river; and 

 that there is no reason to suppose that it will 

 ever do so for the future. There must neces- 

 sarily be some limit or other to the powers of 

 flight of this insect. It would be absurd, for 

 example, to suppose that it could fly in one sea- 

 son as far eastward as England or France, or 

 even as fiir as the Atlantic ocean. Conse(iuently, 

 as it can be proved by historical records that it 

 has never, within the last half century, reached 

 within 112 miles of the Mississipi)i, the fair and 

 reasonable inference is that it never will do so 

 in the future. Because an insect can fly iJ.'A) 

 miles, it would be ridiculous to argue that, 

 therefore, it can fly 700 miles. We might as 

 well argue that, because a man can jump a ditch 

 twenty feet wide, therefore he can jump another 

 ditch which is thirty feet wide ; or that, because 

 a man can easily carry a young calf upon his 

 back, therefore, if he practises daily, he will 

 be able to cany the same calf upon his back 

 when it has grown up to be a cow. 



It will be seen at once, from what has been 

 stated above, that we do not consider the Colo- 

 rado Grasshopper as a permanent denizen either 

 of Kansas, Nebraska, western Missouri, or 

 western Iowa. It is certainly a very remarkable 

 fact that it has invaded these countries from the 

 Rocky Mountain region for three successive 

 autumns, namely those of 1866. 1867, and 1868; 

 and no doubt the young larviB that hatch out in 

 the spring of 1869, from eggs laid in the autumn 



♦In 1851), acciiviling to Mr. J. S. Jlcn-ill, of Oiuiwii City, 

 lowH, it imadcd west :md northweHt Iowa. 



t In 18.07, nrcnrdin;,' fti tile same ffentlemiin, it invaded west 

 anil central 1(A\ a about the last ol August. ' 'S. II. K. ' ' of 

 Paj^e cnunt\-, in the southwest corner of Iowa, says that it 

 invaded that couutN' ' 'verv late in the fall of 1S57. ' '—Prairie 

 Farmer. Ajiril sri, 1868. 



} In ISBf , aiiording to Mr. MeiTill, it extended as far as 

 .Sii)U.\ City, in western Iowa. 



