Insects of Shade Trees and Their Control. 63 
Beetle brood trees left in the area will tend to nullify haphazard 
control work. 
LOCUST BORER.” 
Character and extent of injury.—The locust borer is the most de- 
structive insect of black or yellow locust in some localities. Per- 
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Fie. 42.—Work of two-lined chestnut and oak borer. Section of wood 
from mfin trunk of a dead chestnut, showing the larval mines on the 
outer surface after removal of bark. Beetle and grub at left lower 
corner. (Burke.) 
fectly healthy trees are attacked. The wounds it makes in the bark 
and sapwood stunt their growth. If the attack is severe or continu- 
ous for a number of years, the trees, particularly young saplings and 
branches of larger trees, are killed and their wood is made worthless 
by the wormholes. 
88 Oyllene robiniae Forst, 
