62 Farmers’ Bulletin 1169. 
areas. In sickty trees the insect is very generally found associated 
with the shoe-string root fungus, or previous defoliation, and it un- 
questionably hastens the death of such trees. When weak trees are 
scarce and the beetles are numerous they may attack perfectly 
healthy trees and kill them. 
Habits and appearance—The beetles are on the wing in early sum- 
mer, when they mate and lay eggs, preferably in deep cracks on the 
bark of the: main trunk and branches. Each egg hatches into a flat, 
bigheaded, milky or yellowish white grub (fig. 41, ¢) which burrows 
through the bark and, by the time it is full-grown, by fall, it has 
excavated a burrow up to 3 feet long obliquely and across the grain 
in the inner bark and outer wood. It spends the winter in a chamber 
in the outer bark. Late the following spring it changes here to a 
pupa (fig. 41, d) and about two 
weeks later transforms to the 
adult, which is a dull or brownish 
black beetle (fig. 41,@) one-fourth 
to two-thirds inch long with two 
yellowish lines along the back, 
which burrows its way out of the 
tree and begins life in the open as 
described above. A number of 
such burrows (fig. 42), side by 
| side around the trunk, girdle the 
ig, 41 Twollned chastdut and oak thee and Sever the weeclaawiiem 
borer: a, Adult beetle; 6, antenna of carry food and moisture between 
same; 9, claws of posterior tarsi of fe- F - 
male: | Go same ob males, slat) qe oLOebe and top, and the tree dies in 
pupa. a, b, c, and d, Enlarged; b, ¢, consequence. 
and 9, more enlarged. (Chittenden. ) Remedy (applicable only to 
specially prized, individual, slightly infested trees).—Spray the 
trunks during fall with poisoned kerosene emulsion (p. 12-13). 
Prevention.—In the grove or forest prevention is the only practical 
means of control. This consists of the following measures calcu- 
lated to eliminate the beetle’s favorite breeding quarters (bark on 
freshly felled or dying trees and cordwood) : Remove and promptly 
burn, during the fall, winter, or early spring, the bark (the wood may 
be utilized for any suitable or desired purpose) of all heavily in- 
fested, injured, weak, dying, and dead chestnut and oak trees and 
limbs over as wide an area about the trees to be protected as possible. 
Thoroughly done, this will kill the grubs in these trees, eliminate the 
borer’s favorite breeding places, and reduce the numbers of the beetles 
to such an extent that those remaining will be incapable of effecting 
serious injury. In most cases extension of the area of control opera- 
tions can be achieved only through cooperative or joint action of ad- 
joining owners, and this must be secured for successful results, 
OY 
