CONTROL OF GIPSY MOTH BY FOREST MANAGEMENT. 



39 



Stand and cutting table, Medfleld, Mass. Mixed, hardwood stand, one-tenth 



white oak. 





Original stand. 



Number por acre 



left under plan 



proposed 



Trees which control if in sufficient numbers. 



Trees which 



control 

 on this lot. 



Other species 

 present. 



Number 

 por acre. 



Gradual conver- 

 sion — succes- 

 sive cuttings. 





First 

 (now). 



Second 



(in 20 

 years). 



Class I: 







91 

 29 

 43 



38 

 219 



6 



29 



126 





















Class II: 



White pine. 







32 



105 



1 













Class III: 





Red maple. . 





Class IV: 





















426 



193 



( 2 ) 



1 In the cutting actually made on this lot, black oak was favored as an experiment, so the table does not 

 in this respect conform to the practice suggested in the text. 



2 See p. 39, last paragraph. 



Planting will not be necessary, but cleanings for at least five 

 years (see p. 29), removing all sprouts of Class I trees, will be of 

 great assistance in reducing the amount of food available for first- 

 stage gipsy-moth larvae and in maintaining the altered composition 

 of the stand. It should be stated frankly in this connection that the 

 entomologists consider the removal of all oaks and other Class I 

 trees as the safest method to follow in controlling the gipsy moth 

 by limiting its food plants. The foresters, however, who are work- 

 ing on the problem consider this most undesirable from the stand- 

 point of management. Both agree that the help to be expected 

 throughout the infested region from parasites and other enemies 

 and periodical outbreaks of the wilt disease, combined with other 

 measures of control, may eventually cause the gradual subsidence 

 of the gipsy moth to a normal place among other injurious insects. 



Under the plan proposed, the second cutting will not take place 

 for about 20 years (the end of the rotation), at which time the stand 

 will be cut clear. 



By leaving the chestnut sprouts following the thinning and the 

 final cutting and removing sprouts of oaks or other Class I trees in 

 the cleanings, the representation of trees of this class in the succeed- 

 ing stand should be much reduced. By continuing the same process 

 through succeeding rotations all Class I trees may be removed, and 

 the conversion to a moth- resistant stand would be complete in 80 

 to 140 years. 



