INSECT ENEMIES OF EASTERN FORESTS 47 
moving any pieces of wood in contact with the ground will prevent 
damage in certain types of buildings. 
DRY-WOOD TERMITES 
In a narrow strip close to the coast from Norfolk, Va., southward, 
and along the southern coastal areas of the United States and in Cali- 
fornia south of San Francisco, dry-wood termites damage the wood- 
work of buildings. As a rule this damage is not serious, except in 
southern California and the southern tip of Florida. 
To control dry-wood termites, drench the infested wood with ortho- 
dichlorobenzene, using a saturated rag or mop, or inject the chemical 
into holes bored 18 inches apart in the eaten wood. Several applica- 
tions may be necessary. If the termites are too deep within the wood, 
or if the wood is structurally weakened, it should be replaced with 
timbers that have been preimpregnated with wood preservatives. It is 
advisable to open up the house while treatments are being made, 
since the chemical has an odor that might prove disagreeable in a 
closed room. When orthodichlorobenzene is used for treating fur- 
niture in buildings where food is dispersed or stored, it is well to 
remove the infested material and make the treatments out of 
doors. 
The next best remedy is to dust dry paris green, the less dangerous 
50-percent DDT, or sodium fluosilicate, into holes bored with an auger 
into the infested wood, penetrating to the galleries of the termites. 
If the powder becomes caked because of moisture the treatment should 
be repeated. 
Fumigation with heavy dosages of toxic gases after tightly sealing 
structures exteriorly with heavy paper has recently proved effective 
in killing drywood termites in isolated buildings. Such work must 
be performed by a professional fumigator. 
BARK BEETLE CONTROL 
It has been mentioned before that in the Eastern States bark beetle 
control is less important than in the Western States, where there are 
great areas of mature timber. In the West the methods of bark beetle 
control have been perfected and greatly elaborated to fit special con- 
ditions In Insect Enemies of Western Forests (Keen, 262), these 
methods are discussed in detail, and that work should be consulted for 
a fuller treatment of the subject. In the present publication only a 
brief résumé of methods will be attempted. 
No means are known to save a tree that has been successfully at- 
tacked by bark beetles. The blue stains (see Insects and Diseases p. 
10) introduced at the time of attack by pine beetles, quickly penetrate 
the sapwood, blocking the conduction of water to the crown, and death 
results in 5 to 10 days. Experimentally a few trees have been saved 
after such attack by use of chemicals applied on the bark or introduced 
into the sap stream, but this method is still a matter of laboratory 
experiment. 
Tn the East, bark beetle control methods have been applied to only 
a few species of the tree-killing beetles—the southern pine beetle, the 
spruce bark beetle, the hickory bark beetle, and several species of Lps. 
Outbreaks of these species are sporadic and short-lived, and control to 
be effective must be applied quickly and thoroughly. 
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