130 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



even should no method of preventing locust invasions be found. These 

 plans, as a matter of course, may have to be modified as experience will 

 show to be necessary ; and what is applicable in one section may beun- 

 suited to another — this can only be ascertained by experience. 



Among the questions propounded in the circular (No. 1) which we 

 sent out in the early part of the season, were the following: 



*'No. 12, crops which suffered most.^' 



*^No. 14, crops which suffered least." 



The answers to these questions, so far as received from Minnesota, 

 Iowa, Nebraska, and Dakota, will be found in Appendix 20. From 

 these it appears that crops which suffered most stand about in the fol- 

 lowing ratio : 



Wheat, 100; barley, 33; oats, 30; corn, 26. 



Those which suffered least as follows : 



Pease, 100; corn, 53; sorghum, 33; oats, 30; potatoes, 2. 



While this method of aggregating the replies may and perhaps does 

 present a generally correct idea as to the comparative injury to crops, 

 the ratio cannot be relied upon for several reasons, among which we may 

 mention the following: 



^ crop generally grown in one section is seldom grown in another. 

 Some crops are much less common than others, and hence are not so 

 often mentioned in the replies. If we take Minnesota, from which most 

 replies were received, and where wheat and pease are more largely pro- 

 duced in proportion to corn than in either of the other States named, 

 the ratio will stand as follows : 



Injured most. — Wheat, 100 ; oats, 37 ; barley, 37 ; corn, 9 ; flax, 9. 



Injured least — Pease, 100; oats, 38; corn,31; sorghum, 21; potatoes. 17. 



In Nebraska the ratio is as follows: 



Injured most — Wheat, 100; corn, 32; barley, 14. 



Injured least- — Corn, 100; sorghum, QtQ) pease, 33; wheat 33. 



It is evident, from all the facts we have obtained, that wheat suffers 

 most from the young insects, to which, as a matter of course, the replies 

 alluded to apply ; but that corn suffers most, from the invading swarms, 

 of the field crops. 



The replies are evidently intended to apply chiefly to the question of 

 preference in plants shown by young insects. In reference to this point, 

 we may state, as the result of our inquiries and observations, that they 

 are excessively fond of the vegetables grown in gardens; of the field 

 crops they appear to give a decided preference to wheat and barley over 

 corn and oats. As between the last two the testimony is conflicting, 

 but it appears to preponderate to the view that oats are preferred to 

 corn. There appears to be no doubt that pease suffer least of any field 

 crops ; sorghum and broom-corn appear to stand next in the list of those 

 least liable to injury. The native prairie grass suffers but little from 

 the attacks either of the young or invading insects, while, on the other 

 hand, cultivated grapes appear to be almost as liable to injury as the 

 small grains. 



