10 U. S. DEPARTMENT OF AGRICULTURE BULLETIN NO. 484. 
Hackberry (Celtis occidentalis Linn.). 
Holly, Ainerican (Jlex opaca Ait.). 
Laurel, Mountain (Kalmia latifolia Linn.). 
Locust, Black (Robinia pseudacacia Linn.) 
Locust, Honey (Gleditsia triacanthos Linn.). 
Maple, Mountain (Acer spicatum Lam.). 
Maple, Striped (Acer pennsylvanicum Linn.). 
Mulberry, Red (Morus rubra Linn.). 
Sheepberry (Viburnum leniago Linn.). 
Sycamore (Platanus occidentalis Linn.) 
Tulip (Liriodendron tulipifera Linn.). 
Walnut, Black (Juglans nigra Linn.). 
Shrubs occur frequently as undergrowth in the woods of the in- 
fested region and may have an important bearing on the infestation 
of the trees growing above or around them. A stand of such species 
of trees as are not fed upon until the larve reach their later stages 
might be immune from damage were it not that the larve are en- 
abled to reach these later stages by feeding on near-by shrubs. Most 
of the shrubs which grow in the region die out if sufficiently shaded, 
and the balance occur so rarely in shade or are eaten to such a slight 
degree by gipsy-moth larve that they are unimportant. If forests 
were under management the danger of woods thus being infested 
would be eliminated, because in a properly managed forest the trees 
should be so grown that they produce at all times an amount of 
shade sufficient to preclude the development of shrubs in any numbers. 
Larvee feeding on shrubs which are favored food plants, occurring 
in open land adjacent to woods, might migrate to the woods, but 
would not penetrate very far if the trees of the stands were of any 
but those of Class I. 
The following statement appears on page 27 of Bulletin 250: 
“There is in some cases, at least, considerable variation in suscepti- 
bility of different trees of the same species.” This should be con- 
sidered carefully in connection with any form of management which 
prescribes the removal of certain trees on the ground that they are 
lable to infestation. 
PRECAUTIONS NEEDED. 
Natural enemies of the gipsy moth, in particular those introduced 
from abroad, are constantly increasing in numbers, and their influ- 
ence is a large factor in the control of the moths in woods. It is safe 
to assume that this increase in numbers is going to continue and that 
in the future the character of gipsy-moth damage to woods will 
thereby be greatly modified. 
In view of the above, and of the fact that itis impossible definitely 
to predict the outcome of an infestation under any circumstances, 
it is unwise to attempt to eliminate any particular species out of 
consideration for susceptibility to gipsy-moth attack alone. There 
