164 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



parted. Shortly afterward adverse winds drove back these hordes, or 

 others from the north part of the State, or the neighboring portions of 

 Dakota and Minnesota. The hearts of the I^ebraska farmers sank once 

 more. The Commission replied to such as appealed to them at this time, 

 "No invaders' have left the Northwest; these are but Hocal flights,' 

 and little if any danger is to be apprehended from them." The fear of 

 local swarms, even though they are from the north, is therefore, to a 

 great degree, at least, gone. 



We mention these facts here simply as illustrations of the importance 

 of studying carefully every part of the history of these insects. 



It has been quite satisfactorily ascertained that no ** invading swarms" 

 visited the border States in 1877. That numerous swarms from the 

 north entered or passed over almost every part of the locust area of 

 these States is true, but that none of these were hatched in their native 

 breeding-grounds we think will be clearly shown by what is hereafter 

 stated, and by the record of flights given in Appendix 13. 



In reference to " returning swarms," in the sense heretofore explained, 

 the data for 1877 are somewhat incomplete, as but few reports have yet 

 reached us from British America, to which section a portion would be 

 likely to wend their way if intent on reaching their original hatching- 

 grounds ,• and so far but one or two points in Western Dakota have been 

 heard from. But even without these data there are reasons for believ- 

 ing the return to the native habitats was not so general as was com- 

 monly supposed it would be by those who hold that as a rule there- 

 suiting broods go back to their native home. 



In the early part of the flying-season the departing hordes from that 

 portion of the visited area from Nebraska to Texas, with but few excep- 

 tions, moved northward, as it was supposed they would do; but later 

 in the season, with a change of wind, they turned southward, and the 

 flights in this direction were almost as heavy and as long continued as 

 those which had moved northward. As there is satisfactory evidence 

 that these southward-moving hordes were not invading swarms from the 

 Northwest, they must have consisted in a great measure of those which 

 had previously moved northward. That some did pass onward is shown 

 by the reports of northward flights over Bismarck, of swarms alight- 

 ing in Western Dakota, of flights seen at Cypress Hills, Battletord, 

 and some other points in British America. Yet the fact that none passed 

 to the north of the international boundary east of Bismarck, and that 

 there were such heavy flights southward east of the Missouri, in Da- 

 Dakota and Minnesota, leads to the conclusion that but a comparatively 

 small portion of those hatched in the visited area ever succeeded in 

 reaching their native hatching-grounds. That a considerable portion 

 may have and probably did pass on to the north on the west side of the 

 Missouri, where there are no settlements from which we could receive 

 reports, is more than likely ; and the few accounts we have received 

 from this section indicate that such was the case. 



