THE GIPSY MOTH ON CRANBERRY BOGS. 17 
CONTROL ON UPLANDS. 
After the gipsy moths have reached the second stage, and 
all danger of wind dispersion is reduced to a minimum, heavy in- 
festations may occur on the uplands in the vicinity of cranberry 
hogs, and if heavy enough to cause defoliation the caterpillars, in 
their march for a supply of food, may move in the direction of a 
bog, and owing to the large amount of food necessary to maintain 
the hordes of larvae, may become a serious menace to the bog itself. 
There are several methods of control that may be used to advan- 
tage in such an emergency, and one or more of those mentioned below 
should be adopted in order to protect the bog. 
The woodland border of the bog may be cut back for the space 
of 100 feet or more, and possibly the section of woodland from 
the edge of this cutting to the infested area may be sprayed. If, 
however, this distance should happen to be only a few hundred feet, 
the spraying would not accomplish the desired result, because only a 
few of the thousands of larvae present would consume enough 
of the poisoned foliage to cause death. The others would march on 
in search of more food. 
When such conditions occur, an open ditch on the upland, back 
from the bog border, may be dug, 12 to 15 inches deep and 18 inches 
wide, the earth being thrown toward the oncoming horde of larvae, 
and the side of the ditch nearer the bog being made perpendicular. 
At the top of this perpendicular side a board about 1 foot wide 
should be placed at an angle of 45 degrees, overhanging the ditch, 
supported by stakes driven into the soil; earth should be banked 
on the outside of this board in such a way as to close up all spaces 
at the base of the board caused by the irregularities of the surface 
of the ground. The undersurface of the board and supports should 
be well smeared with a commercial sticky tree-banding material 
before being placed in position. The larvae upon reaching this band 
will fall into the ditch, and should be sprinkled with crude oil from 
an ordinary watering pot. In case of extremely heavy infestations 
it may be necessary to clean out the mass of dead larvae before the 
last hordes reach the ditch. (Fig. 4.) 
If a protective belt is already cut around the bog it is highly 
desirable that all sprout growth be kept down by bruising the sprouts 
from the stumps for two or three years, using a dull ax with which 
to perform this operation, mowing all other small growth close to 
the ground, and burning all the debris. This well-cleaned border 
may help greatly in controlling some of the other insects that breed 
on the upland border, thereby reducing their ravages on the bog 
itself. 
