LD U. & DEPARTMENT OF AGRICULTURE BULLETIN NO. 484. 
gipsy-moth damage. A detailed consideration of the classification in 
this light is interesting and may prove of value in combining pro- 
tective with improvement measures. 
Class I (p. 8) is composed of 26 species which are favored food 
of gipsy-moth larve. Ten of these species, mountain ash, gray birch, 
river birch, boxelder, scrub oak, service berry, dwarf sumac, staghorn 
sumac, glaucous willow, and witch hazel, yield products of low com- 
mercial value and should in any case be eliminated from mixed 
woods. 
Ten of the species in this class are oaks, including the scrub oak 
just referred to. All oaks require the best of forest soils to develop 
well and profitably. Oaks growing on thin soils, rocky ridges, and 
very sandy soil are usually not very vigorous and frequently suffer 
severely from gipsy-moth attack. If oaks were removed from the 
unfavorable sites on which they very often occur and were confined 
to sites best adapted to their requirements, a large amount of gipsy- 
moth food would be eliminated, a better quality of oak would be pro- 
duced, and there would be available a considerable acreage of forest 
land better suited to the growth of other valuable trees. 
The bur oak, chestnut oak, pin oak, post oak, and swamp white 
oak are generally more or less rare and of restricted local occurrence 
in the infested region. On account of their scattered distribution 
they are not of any great commercial importance here. In consider- 
ation of their susceptibility to moth attack and capacity for main- 
taining infestations, they could well be spared from most stands in 
which they occur. 
The white oak reaches the northern limit of its range in the in- 
fested region, but still is one of the most abundant of the oaks. This 
abundance is abnormal and is due to the sprouting capacity of the 
species, resistance to the effect of fire, and current methods of cutting. 
The trees grow very slowly and seem to be particularly favored by 
both gipsy and brown-tail moths. A very large proportion of the 
existing trees of this species could be removed to great advantage. 
The red oak, black oak, and scarlet oak do well in the infested 
region, and it is hoped that the experiments now under way will 
show that there may be conditions under which they may be safely 
grown. 
The following poplars occur in Class I: Aspen, large-tooth aspen, 
and balm of Gilead. These species all demand a large amount of 
light and occur only where it can be procured. As a result they 
generally occur scattered in mixed woods, and pure where they can 
get the necessary start. They grow rapidly, and when they occur 
in any abundance are in good demand for excelsior and pulp manu- 
facture. There is some question as to what extent they should be 
encouraged in view of their susceptibility to gipsy-moth attack. 
