646 REPORT UNITED STATES GEOLOGICAL SURVEY. 



Let us tberefore grant this settinjjin of southerly and easterly winds, 

 which may last until the locusts are winged. When they rise on the 

 wing into the air they are known to move in a general northwest direc- 

 tion. It is highly probable that they are borne along by these, gener- 

 ally southeasterly winds, and pass over on to the plains. Tlie cause is 

 seen, then, to be entirely independent of subsistence ; possil)ly the re- 

 productive instinct causes them to become uneasy, restless, to assemble 

 high in the air and seek the dry, hot, elevated plateau of the northwest. 

 Should this be so, the cause of their migrations is probabl}^ purely me- 

 chanical. Abundant testimony is at hand to show that they are wholly 

 at the mercy of the prevailing winds, and that as a rule the course of their 

 migrations is quite dependent on the direction of the winds, while the 

 course of the winds depends more or less on the season of the year. "We 

 may expect that future research over suflicient territory will show that 

 the June migrations, from the eastern limits of the locust area, will be 

 toward the northwest, and the July, August, and early Septeniber mi- 

 grations, from the Rocky Mountain plateau, will be in a general easterly 

 and southeasterly direction. 



It is not oidy of great scientific interest, but of high practical impor- 

 tance, to collect all facts bearing on the return migrations, in order to 

 know where the locusts go in their return migrations the second year, 

 as we only know that they do fly a certain distance northwestward. We 

 want to ascertain the extreme western limits of this return migration. 

 W^e also want to learn whether they return to their original breeding- 

 places on the eastern slopes of the Rocky Mountains, or whether the 

 westerly winds, if they are westerly, drive them back and scatter them, 

 so that they do not breed extensively. 



It will be seen by the reader that all grounds for a reliable working 

 theory of locust migrations are based on the work of our Signal Bureau 

 and local observers, and that the observations of the meteorologists 

 and entomologists must go hand in hand. The Government has pro- 

 vided a well organized corps of meteorological observers, and we sub- 

 mit that a number of competent entomologists should take the field, un- 

 der Government auspices. Not only should the border States, especiallj'^ 

 Texas, Kansas, Nebraska, Minnesota, and Iowa, employ competent en- 

 tomologists, following the liberal policy of Missouri, which for eight 

 years has had a State entomologist, whose reports have proved of in- 

 calculable practical value, as well as of great scientific interest, but the 

 habits of the locust need first of all to be thoroughly studied in the Ter- 

 ritories, particularly those of Wyoming, Montana, Idaho, Dakota, Utah, 

 New Mexico, Arizona, and in the State of Colorado. A commission of 

 entomologists should be appointed to make a thorough detailed study 

 for several successive seasons of the habits of the locusts in the Terri- 

 tories mentioned. It would seem that the recommendations made at the 

 recent meeting of western governors at Omaha, that an appropriation 

 be made by Congress, and a commission be attached to the existing 

 United States Geological and Geographical Survey of the Territories, 

 is the most feasible and economical method of securing- the speediest 

 and best results. 



Let us for a moment look at the losses sustained in the United States 

 from the attacks of insects. The annual agricultural products of this 

 country by the last census amounted in value to $2,500,000,000. Of 

 this amount we in all probability annually lose over $200,000,000 from 

 the attacks of injurious insects alone. Dr. Riley avers that the losses 

 during IST'I in Missouri t^om locusts, and it will be remembered that 

 only the western third was invaded, exceeded $15,000,000. This 



