180 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



fly northward in greater or less numbers in Southeastern Dakota, but 

 none of them reached the Northern Pacific Eailroad, so far as we have 

 been able to learn, except a light swarm that came down in Trail County, 

 on Eed Kiver. 



On the 7th, the wind changed in Central Dakota and blew toward the 

 south, carrying with it those observed moving in that direction in Ne- 

 braska on the 8th and subsequent days. 



The chief movement of the locusts hatched in Nebraska, in the region 

 of the Platte, occurred between the 1st and 6th of July. The flights 

 were toward the north, but these must have been driven back on the 8th, 

 9th, and 10th. On the 12th the flights in this State were again to tbe 

 north and continued in this direction until the loth, when they again 

 changed to the south, continuing in this direction until the 20th, when 

 the great southern flight occurred over Minnesota, Southeastern Dakota, 

 Iowa, Nebraska, and Kansas. The next day (21st) the flight northward 

 over Bismarck began again and continued until the 28th, when it changed 

 to southeast. 



The change in direction from south to north which occurred in Ne- 

 braska on the 12th, began in Dakota on the 11th. On the 10th the 

 flights throughout the southern portion of this Territory were toward 

 the south; during the night there was a rain-storm and a change of wind, 

 and on the 11th the movement was toward the northwest, except at 

 Cheyenne Agency, on the Missouri Eiver^ where a swarm was observed 

 moving westward. This movement, observed at Cheyenne Agencj', 

 corresponds in the direction taken with what was observed at Standing 

 Rock on the 18th of June. Although neither of these flights appears to 

 have been part of a general movement westward, yet they render it 

 quite probable that a portion at least of the swarms which moved north- 

 ward into Dakota, which could not be traced beyond its bounds in that 

 direction, turned westward on the local currents which are probably 

 flexed here by the Couteau of the Missouri. 



A report from "Dog Foot Station'- (supposed to be Dog Tooth Sta- 

 tion, 30 miles west of Bismarck, on the road to the Black Hills) states that 

 on the 22d of July the locusts were thick there and still coming from the 

 southeast. If this is correct, these may have been the swarms which 

 were seen passing westward at Standing Eock and Cheyenne Agency. 

 But it is quite as probable they were swarms which had moved north- 

 west, on the west side of the Missouri, where there are no settlements 

 or stations from which reports could be received. 



Taking all these facts, in reference to the flights, into consideration, 

 and also the additional fact that but comparatively few locusts were 

 hatched in Dakota, from which to recruit swarms moving south, we are 

 led. to the conclusion that but a comparatively small portion of the 

 lo.^usts hatched in the States south of Dakota, in 1877, ever succeeded 

 in reaching their native hatching-grounds. While the tendency to re- 

 turn appeared to direct their early movements, this year as in 1875, yet 



