CONTROL OF GIPSY MOTH BY EOEEST MANAGEMENT. 29 



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. 



It 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, 

 and a 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 product 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 



