AS MISC. PUBLICATION 213, U. S. DEPT. OF AGRICULTURE 
or stem mothers. These lay eggs early in the spring, and the young, 
which settle on the tender fir foliage and feed, later mature into 
winged and wingless females. The wingless forms deposit eggs which 
hatch later into ‘females that will hibernate, while the winged females 
migrate to the spruce and lay eggs at the base of the needles. The 
young hatching from these cause the formation of the cone-shaped 
galls. About the middle of J uly the forms in the galls become ma- 
ture, full- grown, winged migrants which return to the Douglas fir 
to lay eggs that also 
produce hibernating 
females. Altogether 
there are five stages 
or forms in which 
these Adelges appear 
during different pe- 
riods of their devel- 
opment. 
The species is dis- 
tributed from Brit- 
ish Columbia to Cali- 
fornia and eastward 
into Idaho, Montana, 
Wyoming, ‘and Colo- 
rado. 
Adelges oregonen- 
sis Annand appears 
as a small woolly 
louse on the twigs 
and base of needles 
of larch in Oregon, 
Washington, and 
Montana, but does 
little damage. 
Adelges piceae 
Ratz. attacks the ter- 
minal twigs of low- 
FIGURE 21. = Gals formed Ene Im oe by Cool and plese ir and 
21.—Galls formed on Engelmann spruce by Cooley" noble fir and causes a 
swelling to form 
around the bud, leaving it in a depression and making the twigs 
appear to end 1 in asolid knob. This causes the trees to become Vale 
gnarled. 
Adelges tsugae Annand may be found on the needles and bark of 
western hemlock in California, Oregon, and British Columbia and 
appears as white cottony tufts. 
The woolly pine louse (Pineus pinifoliae Fitch) (Chermes pini- 
corticis Fitch (Chermes montanus Gill.) is found in the Northwest 
from British Columbia to California and in {[daho, Montana, and 
Colorado, where it attacks blue spruce, Engelmann spruce, Sitka 
spruce, and western white pine. On spruce it forms loose terminal 
cone-shaped galls somewhat similar to those of Adelges cooleyi, ex- 
cept that the poorly formed chambers are intercommunicating and 
