CONTROL OF GIPSY MOTH BY FOREST MANAGEMENT. ntl 
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 stumpage 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 be influenced 
by a timber buyer to part with 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.t Still the woods continue to be defol- 
1ated 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.) 
