EFFECTS RESULTING FROM SEVERE LOCUST INJURY. 435 



ripeos and dies early Id the fall, the blue grass gains ground the very 

 first year, and afterward easily retains supremacy. The wide-spread 

 appearance of the Yilfa, following the locusts, has been explained on the 

 hypothesis that the latter brought the seed from the West and passed 

 it undigested with their droppings. The fact that the seed is a line long, 

 and not particularly hard, aside from the other facts in the case, renders 

 such a hypothesis unreasonable. Being an annual, the seed was scat- 

 tered the previous fall, and naturally starting, we may presume, about 

 the time the insects left, the species got the ascendency. 



«* Some i)ersons were quite alarmed at the prevalence of large green 

 and black worms soon after the locust left. Feeding upon purslane and 

 prevailing to an unusual degree, because of the unusual prevalence of 

 this plant, they generally did good by keeping this weed down and con- 

 verting it into manure. In some few instances, however, they swarmed 

 to such an extent as to devour all the purslane, when they attacked 

 grape-vines, and as Mr. Thomas Wells, of Manhattan, Kans., informs 

 me, even cut off corn when it was about a foot high. These worms 



Fig. 108.— WHiTE-LrN-ED Morxing Sphcts. (After Riley.) 



were the variable larvae of the White-lined Morning Sphinx, a pretty 

 moth often seen hovering over flowers at evening. Most insects that 

 naturally feed in spring above ground on low vegetation were killed out, 

 and the only species unaffected by the visitation were those feeding on 

 forest trees, or living in the ground or in the trunks of trees. The 

 White-lined Morning Sphinx was just issuing from the pupa, which had 

 remained undisturbed below ground, when the locusts were leaving. It 

 found the purslane — its favorite food-plant — everywhere springing up 

 and abundant, and its eggs were laid without difficulty, and the young 

 larvae did not in any case lack for food. Asa consequence they pre- 

 vailed to a remarkable degree." 



We noticed that timothy and clover were generally ruined in 1875, 

 and had to be replanted ; but blue grass did not seem to suffer perma- 

 nently, but came up again when the insects left. Mr. Boll reports that 

 in Texas a troublesome weed known as broomweed, which ordinarily 



