CONTROL OF GEPSY MOTH BY FOREST MANAGEMENT. 99 
possible and make a heavy thinning. This has been done to simplify 
spraying, which is effected by a high-power sprayer, resembling in 
size and general appearance the watering carts used in city streets. 
Spraying costs from $8 to $15 an acre, which must be spent each year 
while the infestation continues heavy and is efficacious in stopping 
defoliation at the stage reached when the spraying is done. It gen- 
erally reduces the number of caterpillars but cannot prevent all dam- 
age by them, for its effect is dependent upon the leaves being eaten 
by the caterpillars. : 
Management for moth control may be attempted by making one 
cutting or by successive cuttings. 
One cutting—The expense of spraying may be entirely avoided in 
stands of this character by clear cutting, leaving conifers if desired, 
and planting red or white pine. If this is done it must be followed 
by several cleanings (removing the hardwood sprouts), or the cater- 
pillars in their early larval stages may feed on the hardwood foliage 
and in their later stages attack the pine. 
Tt should be remembered, however, that the gipsy moth increases in 
numbers less rapidly on young hardwood sprouts than on larger trees 
of the same species, whether these are of sprout or of seedling origin. 
When the object of management is moth control, this less rapid 
increase, of course, affects the number of cleanings which are needed 
in young sprout hardwood stands after cutting. 
After various experiments the conclusion has been reached that 
cleanings in the first, third, and fifth years following a clear cutting 
in hardwoods will be ample to insure protection to small planted 
pines and that in many cases the interval between cleanings may 
safely be increased to three years, and the first one postponed until 
the second year after the original cutting. | 
From purely silvicultural considerations the presence of hardwood 
sprouts on the ground during the first summer after clear cutting is 
likely to be beneficial to small planted pines by providing some shade, 
anda cleaning in the second and another in the fourth or fifth year 
following clear cutting would prevent the small pines from being 
killed out or so suppressed that their growth would be seriously 
checked. 
From considerations both of silviculture and of moth protection 
an owner planning to cut clear a mixed oak stand and to plant pine 
should be prepared to make two and perhaps three cleanings, and 
should realize that even more may be necessary. 
The produet of clear cutting on this lot would be about 20 cords 
of good cordwood per acre, which is practically unsalable in this 
locality because of the great amount of cutting now being done. If 
sold, the most that can reasonably be expected for it is $2.50 per 
