63 INSECTS IKJUUIOUS TO STAPLE CHOPS. 



vicinity of their birth. But upon such food becoming 

 scarce they congregate together and in solid bodies, some- 

 times as much as a mile wide, march across the country, 

 devouring every green crop and weed as they go. During 

 cold or damp weather and at night they collect under 

 rubbish, in stools of grass, etc., and at such times almost 

 GBcm to have disappeared; but a few hoars of sunshine 

 brings them forth, as voracious as ever. When, on account 

 of the immense numbers assembled together, it becomes 

 impossible for all to obtain green food, the unfortunate 

 ones first clean out the underbrush and then feed upon the 

 dead leaves and bark of timber lands, and have often been 

 known to gnaw fences and frame buildings. Stories of 

 their incredible appetites are legion ; a friend informs me 

 that he still possesses a rawhide whip which they had quite 

 noticeably gnawed in a single night! 



By mathematical computation it has been shown that 

 such a swarm could not reach a point over thirty miles 

 from its birthplace, and as a matter of fact they have 

 never been known to j^roceed over ten miles. 



As. the nymphs become full-grown they are increasingly 

 subject to the attacks of predaceous birds and insects, 

 insect parasites, fungous and bacterial diseases, as well as 

 being largely reduced by the cannibalistic appetites of 

 their own numbers. When the mature nymphs transform 

 to adult grasshoppers and thus become winged, large 

 swarms are seen rising from the fields and flying toward 

 their native home in the Northwest. This usually takes 

 place during June and early July in the North, and as 

 early as April in Texas, so that it is frequently im.possible 

 to distinguish the broods of the temporary region from 

 the incoming brood which has migrated from the perma- 



