42 
EASTERN SHADE TREE CONFERENCE 
It may thus be seen that insect conditions in the past have paved the 
way for destruction of trees by the storm. The hurricane has in turn 
produced conditions favorable for the increase of bark and timber in¬ 
sects, the full effect of which will probably not be appreciated for several 
years. Trees or parts of trees weakened by the hurricane offer condi¬ 
tions favorable to the increase of the destructive cambium borers. Again 
such of these pests as the two-lined chestnut borer, the hickory bark 
beetle, the bronze birch borer and others will find conditions favorable for 
their increase with the result that further tree damage may be expected. 
Hanging branches offer favorable conditions for the European Elm 
Bark Beetle; limbs which have been twisted or weakened are attractive 
to the Two-lined Chestnut Borer and the Hickory Bark Beetle, and 
many leaning or racked trees may have had their roots torn to such an 
extent that the entire tree may be weakened so greatly as to facilitate 
invasion by one or more of these borers. 
The condition is particularly important in its relation to the spread of 
the Dutch elm disease. There will undoubtedly be an increase in the 
numbers of the European Elm Bark Beetle, the principal carrier of the 
Dutch elm disease. Available evidence indicates that Scolytus sulcatus, 
a native species of bark beetle which develops in apple, plum and elm 
may also be a vector of this destructive elm disease. The present situa¬ 
tion makes it extremely desirable that so far as possible all weak elm 
wood, trees or parts of trees, be cut and burned or at least barked before 
April 1st next in order to reduce the numbers of the principal carrier of 
the Dutch elm disease. Such measures are especially important in 
areas where the disease is known to occur and advisable in other sections. 
In addition to these sanitary measures, another weapon has been 
developed in recent years which may aid materially in combatting the 
European Elm Bark Beetle. It has been shown by experiments that 
timely and thorough applications of arsenate of lead to the twigs of elms 
reduces to some extent at least the danger of European elm bark beetle 
attack, and possible later infection by the Dutch elm disease. 
Soft woods such as the white pine and Norway spruce suffered much 
more in the storm than is the case with the southern hard pines during a 
hurricane. The white pine groves of Massachusetts were particularly 
seriously damaged. In many instances all that remained standing 
were the very youngest trees up to 20 years old and the very largest 
oldest pines which had been the parent seed trees for the groves. Thus 
pine reforestation was set back 40 to 60 years. This means that within 
the next few years a young growth of oak and birches is likely to spring 
