﻿110 EIGHTH ANNUAL REPORT 



[2] It is diflBcuit to comprehend what is meant here, since I have 

 myself shown that much of the country devastated must be in the 

 immediate vicinity of the hot,/dry plains and plateaus in which I be- 

 lieve the species is more particularly at home. I have also expressed 

 my belief that the swarms that occasionally, during Summer, devas- 

 tate the country in which the species is not indigenous, must neces- 

 sarily be the progeny of insects developed at no great distance 

 from the sections they invade, whether they come from Minnesota 

 southward ; from Colorado eastward, or from Texas northward ; and I 

 endeavored to draw the distinction in 1874 between these Summer 

 swarms and the more disastrous Falls warms. On this point the Min- 

 nesota Commission remarks (Special Rep. to Gov. Davis, p. 25): 



It is plain tliat locusts hatched in Colorado and regions to the south and south- 

 •west of Minnesota accxuire wings in time to allow them to reach this State in the 

 former half of June. This is shown by the time when the invasion occurred in 1873, 

 and by the immense flights of locusts which passed over Nebraska and Dakota to the 

 northward in June, 1875. It seems to be a common impression that the locusts which 

 have invaded Minnesota at other times were hatched in Montana, northwestern Dakota 

 •and British America, and this is rendered probable by what few facts we know, and by 

 the time and direction from which they came. These attacks are all represented as 

 coming from the west, north or northwest, and reached the Ked River Settlement in the 

 last week of July, 1818, the Upper Mississippi about the same time in 1856, the western 

 line of the State in the former half of July, 1864, and on July 15th, 1874. In the last 

 three cases the invasions did not reach their farthest limit until a considerable portion 

 ■of the crops had been harvested. 



If Mr. Scudder means that the hordes that occasionally overrun 

 in August and September the whole territory which I have indicated 

 as outside the insect's natural habitat, originate within or upon the 

 borders of that Territory — the country south of the 44th parallel and 

 east of the 100th meridian — then the facts are entirely against his 

 supposition. The late swarms of 1874 are known to have traveled 

 from five to six hundred miles after having reached the more thickly 

 settled country and been observed. The period that elapses between 

 the acquiring of wings and the deposition of eggs is not positively 

 known. From analogy and from a general survey of the facts at 

 hand, I have placed it at from two to three weeks. The Minnesota 

 Commission, in their Special Report to Governor Davis, state (p. 26) 

 that it has been known to be as short as eight days. I think we may 

 safely say, judging from the insects that have hatched out and laid 

 in the same regions in Minnesota, that it will be within a month. 

 Now, the late depo.ution of eggs — as in September and October, in 

 the region that suffered so last Spring — implies late hatching and de- 

 velopment of the parents; and the insects that laid in our western 

 counties, in 1874, must have hatched as late as June 1st, and this late 

 hatching could only occur in the higher sub-alpine regions of the 

 northwest. Of course, in speaking of the hatching of the species, I 



