The Moths and Butterflies 
429 
the back; A. senatoria (Figs. 614 and 615) is like A. virginiensis, but lacks 
the transparent place in the middle of the wing; the caterpillar is black with 
four stripes. All these Anisota larvae feed on oaks, and that of A. senatoria 
also on blackberries and raspberries. Sphingicampa (Adelocephala) bicolor 
is a beautiful moth with brown fore wings and dark-pink hind wings with 
dusky dots, which is not uncommon in the Mississippi Valley and southern 
states; its larvae feed on the locusts and the Kentucky coffee-bean. In the 
southwest are two or three species of the genus Syssphinx resembling Sphingi¬ 
campa bicolor , but one, S. heiligbrodti, in Arizona, has iron-gray fore wings. 
Now unknown in wild condition, the long-cultivated Chinese or mulberry 
silkworm, Bombyx mori, is spread over most of the world, living exclusively, 
however, under the personal care of man. Indeed it is often said that the 
worm is so degenerate, so susceptible to unfavorable circumstances, that 
it could not live out of doors uncared for. As a matter of fact, however, I 
have bred moths from silkworms placed 
exposed on mulberry-trees in California 
immediately after the first moult. And 
these individuals experienced consider¬ 
able hardship in the way of low temper¬ 
atures and dashing rains. The heavy 
creamy-white moths, with wing expanse 
of if inches, take no food at all, and 
most of them cannot even fly despite 
their possession of well-developed wings, 
so degenerate are the flight-muscles from 
generations of disuse. The eggs, about 300, are laid by the female on any 
bit of cloth or paper provided her by the silkworm-growers. They are yellow 
at first, but soon change to a slaty color due to the beginning development 
of the embryo. In the annual race of silkworms, i.e., the variety which 
produces but one generation a year as compared with those others which 
produce two (bivoltins), three (trivoltins), and even five or six (multivoltins), 
the development of the eggs soon ceases, and they go over the winter, hatching 
in the following spring at the time the mulberry-trees begin leafing out. 
The larvae (Figs. 616 and 617) must be well fed with fresh mulberry or osage- 
orange leaves (they may at a pinch be carried through on lettuce) from which 
all rain- or dew-drops should be wiped off. The worms moult every nine 
or ten days, ceasing to feed for a day before each moulting, during the forty- 
five days of larval life, spinning before the last moult (pupation) the dense 
white or golden silken cocoon which is, to man, the silkworm’s raison d'etre. 
In this spinning the thread is at first attached irregularly to near-by objects, 
but after a sort of loose net or web has been made the spinning becomes 
more regular, and by the end of three days a thick firm symmetrical closed 
Fig. 617.—Mulberry silkworm, show¬ 
ing front view of head and thorax. 
(From life; natural size.) 
