56 PRACTICAL FORESTRY IN THE ADIRONDACKS. 
and wind. This is especially true where a considerable amount of Pine 
occurs, for in felling the heavy trees large openings are inevitably made 
and the tops, saturated with pitch, are very inflammable. 
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INSECTS. 
The Spruce forests of the Adirondacks have at different periods been 
attacked by what is locally known as the Spruce blight, the cause of 
which is now recognized to be a small bark beetle, Dendroctonus rufi- 
pennis Kirby. It appears that in certain sections of New York State 
large numbers of. Spruce died between 1840 and 1850 and that there 
was a repetition of the same trouble about 20 years later. Between 
1875 and 1880 the forests were again attacked by borers, and during 
the following 10 years a large amount of valuable timber was killed. 
The borers seem to attack sound, thrifty trees as soon as they begin to 
work in large numbers, but they do not, as a rule, attack trees under 
about 10 inches in diameter. The death of the timber is caused by the 
numerous galleries made by the borers between the wood and bark, 
which virtually girdle the trees. The forests of northern New Hamp- 
shire and Maine are said to be subject to the attacks of this insect at 
the present time, and it would not be surprising if there were another 
outbreak of the pest in the Adirondacks. 
The Tamarack in the Adirondacks has suffered even more from the 
attacks of insects than the Spruce. In fact, practically all the large 
timber has either been killed or is dying from the work of the larve of 
a sawfly, Vematus erichsoni Hartig, which entirely defoliate the trees. 
This pest made its appearance about 1882 and still continues its 
destructive work. It is now difficult to find living specimens of Tama- 
rack over 10 inches in diameter, and a large number of the small trees 
show some injurious effects from the worm. (See Pl. VII, fig. 2.) 
WATER. 
It is well known that the flooding of the shores of streams and lakes 
during the season of vegetation destroys the timber. About bodies of 
water where the surface level has been raised by dams built for logging 
purposes there is usually a fringe of dead timber. Where, however, the 
water is raised only in the early spring and let out immediately after 
the logs have been driven, the damage is very small. When the water 
is raised above its normal level by dams in the early winter there is fre- 
quently a certain amount of damage by the washing of the shores 
during heavy winds. (PI. XV, figs. 1 and 2.) 
ICE. 
While the injury caused hy the submerging of the roots during the 
season of vegetation is well known, the damage resulting from high 
water in winter has not been generally recognized. The reason for this 
