the openings of their galleries in the bark. But this is laborious and 
impracticable against small borers like Agrilus. 
Our chief reliance is in preventives, in the employment of mechan- 
ical precautionary measures that will serve the double purpose of 
effectually deterring wood- and bark-boring insects from boring into 
or depositing their eggs on the trees and from effecting their egress 
through the bark once they have begun their attack, and in other 
mechanical measures. 
The most important requisite 1s clean culture; in fact, little of sub- 
stantial value can be accomplished remedially without it. Owners 
of forest land who have sufficient financial interests at stake will do 
well to cut down the dead and to trim the injured trees. For the pro- 
tection of chestnuts all dead oak as well as chestnut trees, and such 
as are infested and too feeble to recuperate should be cleared away 
and burned. Much can be accomplished by simply removing the bark 
of the dead timber. 
Unfortunately, in too many cases storm-killed and injured trees 
are carelessly permitted to remain as a nidus for borers, and when 
this wood becomes too dry and the bark too loose for the insects, 
those that have bred in them emerge and migrate to neighboring 
living trees. 
A frequent and potent source of injury is in the almost universal 
custom of permitting cut or sawed timber to season without remov- 
ing the bark, a custom followed alike by the forest landholder, the 
general farmer, and the mill owner. Even the family woodpile may 
become a center of infestation. Wood that is cut during winter 
becomes infested the following spring and early summer, and when 
left to season through the summer and autumn months should be 
consumed or otherwise disposed of before the following April. <A 
few cords of wood may develop enough boring insects in a single 
season to infest and injure acres of woodland. Another source of 
infestation is in carelessness in permitting dead trees to come in con- 
tact with living trees and in bruising or otherwise injuring healthy 
growth. 
The progeny of insects that deposit their eggs in one season so 
loosen the bark that it may easily be removed and burned before the 
following spring, thus destroying millions of the insects before they 
have an opportunity to issue and lay their eggs for the destruction of 
valuable trees. 
In Kurope it is customary for foresters to girdle a few trees here 
and there and leave them standing as traps for such beetles as may 
not have been destroyed with their host trees, These trees in turn 
are decorticated the following year and others treated in like manner 
should appearances indicate the advisability of this course. 
