11 
SIXTH-STAGE LARVA 
Newly molted larva 25 mm. long. Head black with bluish tinge ; 3 mm. wide. 
Markings similar to those of previous stage. White blotches larger and more 
conspicuous, and brown tubercles brighter in color than on fifth-stage larva. 
White mottling of black body, giving it a light bluish-gray appearanr-e. 
The sixth-stage larvae feed for five to six days, eating the entire 
leaf tissue, and leaving only the coarser veins. As in the case with 
the previous stages, the sixth-stage larvae construct webs across the 
fissures of the bark, under which they molt. 
SEVENTH-STAGE LARVA 
Newly molted larva 35 mm. long. Head black with a bluish tinge, 4.5 mm. 
wide. The caterpillar has the same appearance as in the sixth stage, but 
is considerably larger and more conspicuous. (PI. 1, 1.) 
The seventh-stage larva feeds for about seven days, then spins a 
loose cocoon in which to pupate. 
THE PUPA 
Pupa (PI, 1, 2, 7) 20 to 25 mm. long and 5 to 7 mm. wide at base of abdomen. 
Shining black, covered with tufts of long, silky, white and golden hairs, except 
on venter, where hairs are scarce. Usually on each abdominal segment occurs 
a row of two to five light-brownish spots, variable in size, and number and 
occasionally missing. 
Pupation takes place after the seven larval stages which have 
been described, both male and female moths developing from sev- 
enth-stage caterpillars. The cocoon, the spinning of which may 
occupy from several hours to two days, is very loosely made, and 
the pupa within is plainly visible. It is frequently constructed so 
as partially to bring together the two edges of a leaf, as shown in 
Plate 1, 7. The cocoons occur not only on leaves, but are also found 
in the crevices of bark, in rubbish near trees, and on buildings, 
fences, and in other convenient places. (Fig. 3, A.) The adult 
emerges about 10 days, on an average, after construction of the 
cocoon is begun. 
FOOD PLANTS 
Field observations and feeding experiments have been made at 
the Gipsy Moth Laboratory to determine the favored food plants 
of the satin moth in New England. As a result the trees here 
named have been listed in the order of their preference as food 
plants of the satin moth. 
FAVORABLE 
Lombardy poplar Populus nigra italic a. DuRoi. 
Carolina poplar Populus deltoides Marsh. 
Balm of Gilead Populus candicans Ait. 
White poplar Populus alba L. 
Large-tooth aspen Populus grandidentata Michx. 
Quaking aspen Populus tremuloides Michx. 
Golden willow Salix vitellina L. 
PARTIALLY FAVORABLE 
Scrub oak Quercus ilici folia Wang. 
Black oak Quercus velutina Lam. 
