GRASSHOPPERS AND OTHER INJURIOUS INSECTS OF 1911 AND 1912. 



75 



while the tract "C" was plowed in the Spring. It appears possible that this 

 spring plowing may have affected the pupas at a critical period and thus ac- 

 counted for the absence of the weevil. 



N. 



Natural / 

 drainage. 



A. 



.A Ion njars/i 



w. 



n 



Wirr?? 

 residence 



hon land 



B 



"VelveXChaff 

 Wfteat 



(Falinowed) 



C: 



''Blue: Stem" 

 /Wheat 

 .• (Spring 

 Plowed) 



D. 



"Blue Stem" meat 

 (Fall PLoyye±) 



PrivCLte fjoixii. 



Fig. 56. Plan of wheat fields injured by H. ochreiis. Somes. 



This species of Sphenophorus, I have found rather sparingly in Iowa, and 

 the southern parts of Minnesota during the past year, but never in large num- 

 bers such as were here presented. I may say that within a space one rod wide 

 and three rods long, we picked over 100 of the weevils and some others escaped. 

 I have always heretofore found the insect in low ground and associated with 

 the "common rush" (Scirpus) of such marshy habitat. In the more southern 

 states, it has been known to attack corn, but so far as I know, this is the first 

 instance in which it has been known to attack wheat. The damage will doubt- 

 less be local and confined to fields in low ground such as the one here consid- 

 ered. Methods of control which suggest themselves are the planting of some 

 less attractice crops on these low fields, such as flax, potatoes, beets or rape; 

 drainage of the areas and possibly spring plowing and the thorough cultiva- 

 tion of the field." 



