CONTROL OF GIPSY MOTH BY FDBTEST MANAGEMENT. 11 



is sufficient cause for removing many trees on the ground that they 

 are mature, dying, defective, unfavorably situated, or interfering 

 with the development of better trees. It is not good forest policy to 

 remove any thrifty young tree until it has been given every oppor- 

 tunity to yield a return on the investment which it represents. To 

 remove such young trees would be similar to abandoning a crop of 

 young potato plants because of the appearance of the potato beetle. 



Sawmill men have frequently induced owners to sell standing white 

 pine by asserting that the trees were doomed to destruction by the 

 presence of the gipsy moth. An owner believing this is likely to be 

 induced to sell his stump age at whatever price the sawmill man may 

 choose to offer him. This practice has resulted in the cutting of im- 

 mature trees which would have yielded a greater profit to the owner 

 if permitted to mature. No owner who is unfamiliar with the action 

 of the gipsy moth in woods should permit himself to he influenced 

 by a timber buyer to part toith thrifty trees of any sort on the ground 

 that the trees are liable to attack by gipsy moths. The advice of 

 State and Federal officers who are familiar with the problem is avail- 

 able to any owner of woods in the region. 



The poor condition of woods, combined with the damaging effect 

 of gipsy-moth attack, makes improvement and protective measures 

 imperative. Introduced enemies of the gipsy moth are becoming well 

 established and are doing effective work, and the wilt disease pre- 

 vails throughout the region. 1 Still the woods continue to be defol- 

 iated by gipsy moths, and further protective measures are in demand. 



Any plan for the silvicultural improvement of stands of trees 

 should provide for the removal of dead, dying, mature, and defective 

 trees, trees standing in unfavorable situations, and trees of low com- 

 mercial value. It should provide for the replacement of these re- 

 moved trees with thrifty trees of high commercial value well adapted 

 to their environment. It should also provide for a compact stand of 

 trees without overcrowding. Such action alone would constitute a 

 protective measure of great value, but if it could be extended to em- 

 brace the removal of trees and conditions favorable to the develop- 

 ment of the gipsy moth and the replacement of these by trees and 

 conditions unfavorable to the gipsy moth, a still greater degree of 

 protection would be provided. 



APPLICATION OF FOOD-PLANT DATA TO INDIVIDUAL SPECIES. 



The classification of trees on the basis of the extent to which they 

 are fed upon by gipsy moths (p. 8-10) is one which may well be 

 used in the production of stands of trees which shall be free from 



1 Glaser, R. W. Wilt of gipsy moth caterpillars. In U. S. Dept. Agr. Jour. Agr. Res., 

 v. 4. No. 2, p. 101-128, 17 fig., May 15, 1915. (P. 102.) 



