322 



before section I of the American Association for the Advancement of 

 Science. 



During the present summer (1891), and especially during the past six weeks, the 

 papers have contained numerous reports concerning serious grasshopper ravages iu 

 various parts of the country, in some cases the reports being quite sensational and 

 well calculated to create apprehension as to the safety of our crops and as to the 

 possibility of serious locust devastation this fall or next year. I have felt that per- 

 haps a few words indicating the exact state of the case and summarizing the investi- 

 gations made, whether by agents of the Department or others, will be of service in 

 giving our farmers the true condition of things. While, from the investigations 

 made a year ago and the reports of locust injury it did not seem probable that there 

 could be very much foundation for the reports of the present year, I deemed it quite 

 desirable to endeavor to ascertain the facts as closely as possible. Accordingly Prof. 

 Lawrence Bruner was instructed to examine fully the regions in the northwestern 

 States where the injuries were reported, and he has been over eastern Colorado, 

 eastern and North Dakota, western Minnesota, and portions of Montana and Wyo- 

 ming. Prof. Herbert Osborn was instructed to visit the western parts of Kansas and 

 investigate the southwestern portion of the State, examining all localities from 

 which any reports of injury could be obtained. Prof. F. H. Snow and Prof. E. A. 

 Popenoe, on behalf of the State authorities in Kansas, thoroughly examined the 

 section of country in southeast Colorado, passing over the country embraced in 

 northern Kansas, and thus connecting the territory covered by Professors Bruner 

 and Osborn, so that it may be stated that the plains region from northern Minnesota 

 west to Montana and south to the Arkansas River, has been pretty thoroughly exam- 

 ined. Mr. Nathan Banks was instructed to visit south Texas and New Mexico to 

 inquire into the reports of injury iu those sections. 



It may be stated in brief that the depredations in eastern and southciisteru Colo- 

 rado have been due to the exceptional multiplication of the Long-winged Locust 

 (Dissosteira longipennis). This species always occurs in that section, and some of the 

 first insects which I collected in Colorado on my first visit in 1867, were of this 

 species, and are now in the National Collection. It has never yet been reported in 

 such innneuse and injurious numbers, and its work the present year furnishes 

 another illustration of the fact that we never know when a species that has hitherto 

 been looked upou as harmless may become seriously injurious to agriculture. Dur- 

 ing the latter part of July millions of pupse aud full-grown larvje of this species 

 were found ranging over large areas of eastern and southeastern Colorado, moving 

 iu vast bodies all the way from Akron to the Arkansas River to the south. The 

 insects moved iu a body iu various directions, choosing, as Prof. Bruner reports, the 

 roads for their line of march rather than the prairies. Normally this species fre- 

 quents partially bare hill slopes and plains where the grasses are scant, and Prof. 

 Bruuer's view of the matter is that the past few years have been favorable to its 

 excessive multiplication, but that during the present year the exceptionally heavy 

 rains which have occurred in that region have caused an unusually abundant 

 growth of grasses and other vegetation, and the locusts have been compelled to 

 move in search of more open country and have frequented the roads, upon which 

 they congregated and which they followed in vast bodies. He found, in going some 

 distance away from the roadways, where the vegetation was at all rank, that but 

 few insects were found. This species, in size aud length of wing, much more closely 

 resembles the migratory and destructive species of Europe and some other countries 

 than does the Rocky Mountain Locust {Calopteniis sjrretiLs), aud there seems to be no 

 particular reason why, at times, it should not become destructive and fly in vast 

 swarms from one locality to another. So far as past experience justifies calculation, 

 however, it will not do so, audi think there is little reason to fear any continued 

 and widespread injury from this species. 



