SPRUCE BUDWORM AND WHITE PINE WEEVIL 153 
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this stage for a period which varies with conditions of 
temperature and moisture. This transformation in the region 
of Orono was at its apex during the summer of 1919 in the 
latter part of July, although a few of the insects were still larve 
in the middle of August. The first adults of the new generation 
were obtained July 30, but these were but recently transformed 
from the pupz and from a considerable number of infested leaders 
which were under observation; no adult emerged before August 
5th. The adults continue emerging from the old hosts throughout 
the month of August and to a decreased degree during early Sep- 
tember, while a few derived from eggs laid late, pass the winter 
in the old leaders either as larve or as young, immature adults. 
By far the greater number, however, emerge before September and 
on the approach of cool weather, seek some sheltered place in 
which to pass the winter. 
THE BOOM WALKER 
The care of one or more fin booms is intrusted to a watchman who keeps 
them in repair and clears away mee or drift that catch on the fins or braces. 
Photo by Maine Forestry Dept. 
The leader which has been attacked at first shows no signs of 
injury aside from the exudations of pitch already mentioned. The 
new growth begins normally, but soon after the larve begin feed- 
ing, the new growth above the injury begins to wilt, and soon turns 
brown and dies. As the larve continue feeding, the terminal con- 
tinues to die farther and farther down and usually the entire leader 
down to the first whorl of laterals is killed. Occasionally, when the 
number of larve is greater than usual, they may continue their 
work of destruction below the upper whorl of laterals. In this 
manner, two years’ growth and rarely three years’ growth is 
killed. 
