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6 THE DYING OF PINE IN THE SOUTHERN STATES. 
There are from three to five generations annually. The first 
generation begins with the eggs deposited by the first beetles that 
fly and attack the trees in the spring and by those of the overwin- 
tered broods as they make successive attacks during the spring 
and early summer. 
The second generation begins with the eggs deposited by the 
adults of the first generation and so on until cold weather stops 
their activities. 
At all times there is a more or less complex overlapping of gen- 
erations, so that there is a continuous emergence and attack during 
Fic. 1.—Egg galleries a larval mines of the southern pine beetle: a, Entrance; 6, entrance burrow; 
c, egg gallery; d, normal larval mine; e, abnormal larval mine; /, terminal; g, ventilating burrows. Slightly 
reduced. (Author’s illustration.) 
the entire period of activity; consequently a continuous dying of trees 
within the infested areas. 
Under average or normal conditions of the activities of this beetle 
a few scattering trees are killed by it each year in nearly every 
county throughout the Southern States where the pine is common. 
If, however, there are from any cause favorable conditions for the 
multiplication of the insect, it is thus able to kill groups of trees, and 
if these groups Increase in number and size the following year they 
constitute the danger signal of an outbreak which may result in 
widespread depredations. Therefore it is a most destructive enemy 
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