98 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



As the time of ovipositing varies with the latitude, .so the 

 hatching of the eggs occurs from the middle or last of March 

 in Texas till the middle of May or first of June in Minnesota 

 and Manitoba. Until after the molt of the first skin, and often 

 till after the second or third molt, the young nymphs are con- 

 tent to feed in the immediate vicinity of their birth. When 

 the food becomes scarce they congregate together and in 

 solid bodies, sometimes 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 seem 

 to have disappeared; but a few hours 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 under- 

 brush 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 ! 



As the nymphs become full grown they are increasingly 

 subject to the attacks of predaceous birds and insects, insect 

 parasites, fungous and bacterial diseases, and are also 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 impos- 

 sible to distinguish the broods of the temporary region from the 

 incoming brood which has migrated from the permanent region. 

 Although the eggs for a second brood are sometimes laid, these 

 seldom come to maturity, and the species is essentially single- 

 brooded. 



The Lesser Migratory Locust 



Besides the Rocky Mountain locust there is only one other 

 species that truly possesses the habit of migrating, though to 

 a far lesser extent, and which is therefore known as the Lesser 

 Migratory Locust (Melanoplus atlantis Riley). It is considerably 



