HABITS OF YOUNG LOCUSTS IN TEMPORARY REGION. 233 



of remarkably active powers from the moment tbey leave the egg, yet 

 so long as provision suffices for them on their hatching-grounds the 

 young remain almost stationary and create but little apprehension. As 

 soon, however, as the supply of food in these situations is exhausted, 

 they commence to migrate, frequently in a body a mile wide, devouring, 

 as they advance, all the grass, grain, and garden-truck in their path. 

 The migrating propensity is not developed until after the first molt, and 

 c^'^.en not till after the second or third. Up to that time they are con- 

 tect to huddle in warm places, and live, for the most part, on weeds, and 

 especially on the common Dog-fennel or May-weed [Maruta) where it is 

 present. 



*'The young locusts display gregarious instincts from the start, and 

 congregate in immense numbers in warm and sunny places. They thus 

 often blacken the sides of houses or the sides of hills. Tbey remain 

 thus huddled together during cold, damp weather. When not traveling, 

 and when food is abundant, or during bad, rainy weather, they are fond 

 of congregating on fences, buildings, trees, or anything removed from 

 the moist ground. They also prefer to get into such positions to un- 

 dergo their different molts. In fields they collect at night or during 

 cold, damp weather, under any rubbish that may be at hand, and may 

 be enticed under straw, hay, «&c., scattered on the ground. Old prairie- 

 grass affords good shelter, and where a wheat- field is surrounded with 

 unburned prairie, they will gather for shelter along the borders of this 

 last." 



It is more particularly while they are yet small, or in what are de- 

 scribed in Chapter X as the first, second, and third stages, that the young 

 locusts hide at night, and, during unfavorable weather, at day also. In 

 windy weather thej^ are fond of gathering and secreting under any shel- 

 ter, or in crevices and inequalities of tbe soil. At such times farmers too 

 often conclude that tbe pests have perished and vanished ; but a few 

 hours of pleasant, sunny weather will bring tbe insects to sight again 

 and dispel the delusion ^ When very vigorous and numerous they grad- 

 ually move across a field of small grain and cut it off clean to the ground 

 as they go, appearing to constantly feed. But when diseased or sickly,, 

 as in 1877, they gather in bare and sunny spots and huddle and bask 

 without feeding. The very cold, wet weather that is prejudicial tp them 

 is beneficial to the grain, and under such circumstances it generally 

 grows so rank and rapidly that they make little impression upon it. 



It is when they are abundant and vigorous enough to bare the ground 

 of vegetation, and this principally after they are half- grown, that the 

 habit of migrating in large bodies is developed. In 1877 scarcely any 

 disposition to migrate was shown, and this was in strong contrast with 

 what occurred in 1875. In a year like this last, when tbey are vigorous 

 and abundant, their power for injury increases with their growth. "At 

 first devouring the vegetation in particular fields and patches in tl^.e 

 vicinity of their birthplaces, they gradually widen the area of their 



