116 PESTS OF GARDEN AND FIELD CROPS 
with washing the seed cane with whale-oil soap. Remnants of cane in 
the fields, and Johnson grass in or near by, should be burned. 
The Clover Root-borer (Hylastinus obscurus Marsh.) 
In the Central states clover is subject to considerable injury by this 
insect, the presence of which is seldom recognized. The adult beetle 
is small, dark, and cylindrical. 
Coming out in the spring from 
clover roots, in which it has 
passed the winter, it lays eggs 
in shallow cavities which it ex- 
cavates in the sides of the larger 
roots of clover plants in the 
same or adjoining fields. The 
grubs that hatch from these eggs 
burrow in and through the roots, 
| 
Fic. 82. — Adult of the 
Clover Root-borer. En- 
Fic. $1.— Work of the Clover Root- larged and natural size. 
borer. Original. Original. 
sometimes completely destroying their central parts and killing 
the plant. : 
In the latter part of summer the grub changes to a pupa, from which a 
beetle emerges in fall, but remains in the root until the following spring. 
Only two-year-old plants are likely to be attacked. Plowing a badly 
infested field at once after haying will kill many of the grubs, because 
the roots will be turned up and dried out. Pasturing a field serves to 
