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THE AMERICAN ENTOMOLOGIST. 



THE "COLORADO GRASSHOPPER.' 



Kditovs Amevicaii Eidomologiit : 



You have, perhaps very naturally, arrived at 

 some quite erroneous conclusions respecting 

 the peculiarities of the above named insect. 

 First, impliedly, that its origin is confined to 

 Colorado ; second, that its " native home is in 

 the canons of the Rockj' Mountains;"' and, 

 third, that it deposits its eggs at various points 

 in its flight. 



The "Hatefnl'' (new title to ns) Grasshop- 

 per—by some said to be identical with tlie 

 Egyptian Locust in appearance and habits — is 

 common to all this western or rainless region, 

 one-third of the United States, but its breeding 

 place is upon the hot, parched plains and 

 table lands', from four to six thousand feet 

 above the sea, instead of in the canons of the 

 mountains. The greater the heat, the more 

 they flourish. Though they endure consider- 

 able cold and live, they are at the same time 

 exceedingly sensitive to its efiects; becoming 

 torpid in frosty nights or in snow storms, and 

 reviving to active life in the succeeding hot 

 sunshine. The swarms that devastate the 

 country in their flights are invariably natives of 

 sandy plains or basins, comparatively destitute 

 of vegetation, where the direct and reflected 

 heat of the sun's rays in summer are more in- 

 tense than you ever experience in the vernal 

 valley of the Mississippi. The humidity, how- 

 ever, is very much less ; the air being like that 

 of a furnace. In such places, and on the hottest 

 days, the Grasshopper is the most active, and 

 then it attains its greatest perfection. AVlien it 

 has reached a certain stage in its existence, it 

 takes to flight. Those hatched in the same lo- 

 cality, and necessarily under the same climatic 

 Influences, rise iu the air about the same 

 time, but they do not move in concert. Their 

 course is directed by the prevailing winds more 

 than by any other influence. Consequently, in 

 this country, it is generally from northwest to 

 southeast. They alight or move forward at 

 pleasure, each individual upon its own account. 

 Many of them fly at an immense height. When 

 on the liighest peaks of the snowy range, four- 

 teen to fifteen thousand feet above the sea, I 

 have seen them filling the air as much higher as 

 they could be distinguished with a good field 

 glass, glistening in the sunlight like snowflakes. 

 In crossing the snowy ranges countless myriads 

 of them perish. Nearly all that alight for food 

 become so chilled that they arc unable to rise 

 again, and in a few days they die. On the great 

 snow fields it is notliing uucommcui to see the 



dead so plentiful that they might be shoveled up 

 by wagon loads. 



AYlien the season comes for depositing their 

 eggs, the swarms which happen to be in favor- 

 able localities, proceed to do so, after which 

 most of them soon die and the pest disappears. 

 Some doubtless continue their flight. If the 

 succeeding winter is mild, young Grasshoppers 

 may be found upon sandy, sunny hillsides 

 long before spring, but the great swarms appear 

 with the earliest vegetation. Then it is they 

 are most destructive. It is a common belief 

 that a young Grasshopper eats more than half a 

 dozen full grown ones. They feed and grow, 

 and in due time take flight, as did the genera- 

 tion before them. But few Grasshoppers are 

 hatched in the mountains, properly speaking. 

 It is true they do iu some of the valleys, up to 

 an altitude of seven or eight thousand feet — 

 possibly sometimes to nine thousand — but they 

 usually come out so late that the frosts of the 

 following fall catch them before they take 

 flight. As an illustration, the J\Iiddle Park of 

 the Rocky Mountains is a great basin, bowl- 

 shaped, Avith a single notch broken out of its 

 western rim. Otherwise, it is surrounded by 

 suowy mountains. In 1867, it was invaded by 

 swarms of Grasshoppers from the direction of 

 Utah, which deposited their eggs all over it. In 

 its lower portion the young began hatching 

 about the first of July. They attained maturity 

 and took flight in August. Their hatching 

 ground was from six to seven and a half thou- 

 sand feet above the sea. Further up toward the 

 rim they came out later, and at nine thousand 

 feet they did not appear until the last of Au- 

 gust. September frosts and snows caught them, 

 and they never left their native ground. About 

 the same time these latter hatched, immense 

 swarms of full grown insects came again from 

 the west, but instead of alighting in the Park 

 they drifted up against and upon the snowy 

 range east of it, where they perished in count- 

 less millions. 



In August, 18G4, this country had its worst 

 visitation of "Hatefnl Grasshoppers." They 

 had hatched iu the valleys of the Upper Mis- 

 souri, from six hundred to eight Imndred miles 

 distant, and swept over Colorado with a solid 

 front. They ate up late crops and then depos- 

 ited their eggs and died. In the spring of I860, 

 their progeny came out of the ground with the 

 early crops, which tliey devoured. When about 

 one-third grown they were attacked by an Ich- 

 neumon Fly, which stung them in the back, de- 

 positing one or more eggs. The product of 

 these destroyed probably one-half or two-thii-ds 



