﻿8 BULLETIN" 8, U. S. DEPARTMENT OF AGRICULTURE. 



to corn he reported that the crop was attacked by these worms. In 

 this case no specimens accompanied the complaint. 



It goes without saying that the beetles are found and must develop 

 where very little corn is grown, but time has shown that there is 

 little danger to be apprehended from these. 1 



Quite recently Mr. C. N. Ainslie, of this bureau, has found slight 

 injury to corn in fields in Nebraska where this crop has followed 

 small grain. 



DEPREDATIONS ON LAND SUBJECT TO OVERFLOW. 



The frequent submergence during fall, winter, or early spring, 

 even for weeks at a time, of fields in which the eggs of these beetles 

 have been deposited does not seem to affect such eggs in the least. 

 Throughout the country north of the Ohio and Arkansas Rivers it 

 is these low bottom lands that are kept most continuously in corn, 

 and therefore it is here that in later years the danger from the pest 

 is greatest. This is not, so far as now known, true of the lower 

 Mississippi Valley, for the reason that planters there rotate with 

 cotton, otherwise the ravages of the insect would probably be felt 

 there as well as in the more northern States, as the writer has ob- 

 served the beetles feeding on the pollen of the cotton bloom. Thus 

 we see that throughout the country it is only where crop rotation 

 is neglected that damage is at all to be feared. 



1 Possible origin of a corn-feeding race. — It will be noticed that Mr. B. D. Walsh, the 

 first State entomologist of Illinois, found three of these beetles in central Illinois many 

 years prior to 1866 (Practical Entomologist, vol. 2, p. 10, 1866). Mr. Ottoman Reinecke, 

 of Buffalo, N. Y., wrote the author in 1893 that he had, prior to 1880 and for some 

 years, collected the beetles in abundance on willow along the margin of a creek near the 

 city during July and August ; while Mr. W. II. Harrington wrote the author years ago of 

 his finding them in Nova Scotia. Thus it is clearly shown that the eastward advance each 

 year, as previously recorded, does not represent the real advance of the species. It rep- 

 resents the advance of a race that feeds on the pollen and silk of corn, some of whose 

 larvse develop in the roots, the adults from these spreading from field to field and under 

 favorable conditions giving rise to myriads of worms that feed on the roots and destroy 

 the crop. The origin of this race appears to have been the prairie country in Illinois, 

 which in many places begins at the Mississippi River and extends into northwestern 

 Indiana. It is true that the first reports of injury to the roots of corn by the larvae 

 came from Eureka and Kirkwood, Mo., both of which are near: St. Louis; but just across 

 flic Mississippi River in Illinois are wide stretches of prairie country which near the 

 river are subject to overflow. 



ADDITIONAL COPIES of this publication 

 iL may be procured from the Superintend- 

 ent of Documents, Government Printing 

 Office, Washington, D. O, at 5 cents per copy 



WASHINGTON : GOVERNMENT PRINTING OFFICE : 1913 



