CHAPTER XI 



INSECTS INJURIOUS TO CLOVER AND ALFALFA.* 

 The Clover Root-borer f 



THE Clover Root-borer is practically the only insect pest 

 which seriously injures clover roots. It has long been known as 

 a clover pest in Europe, but was first noticed in this country in 

 western New York in 1876, whence it has spread southward to 

 West Virginia and westward to Illinois and southern Michigan, 

 and has also been injurious in Oregon. 



Life History. During the winter the beetles may be found 

 hibernating in their burrows in infested clover roots. They are 

 not readily distinguishable, for they are scarcely one-eighth 



Fio. 158. The clover root-borer (Hylastinus obscurus): a, adult, natural 

 size at right; 6, larva or grub, c, pupa much enlarged. (After Webster, 

 U. S. Dept. Agr.) 



inch long, and are of a reddish-brown color much like that of the 

 burrow. With the warmer weather of spring they commence 



* See The Insect Pests of Clover and Alfalfa, J. W. Folsom, 25th Report 

 of the State Entomologist of Illinois, pp. 41-124, and Bulletin 134, Illinois 

 Agr. Expt. Station. 



t Hylastinus obscurus Marsham. Family Scolytida. 



189 



