LIBRARY

LEPIDOPTERA 493
Guerin, is another valuable wild and semidomestic species which has been
collected and reared in China and Japan for centuries. It is easily cultivated
in the open and was introduced into Europe in 1861. It feeds chiefly on deciduous
oaks, has one or two generations a year, and produces the light buff Shantung
silk. The Himalayan oak silkworm, A. roylei Moore. is another Indian
oak-feeding species closely resembling the preceding with which it freely
hybridizes in confinement. The white cocoons are encased in a hard envelope.
Expanse 124-190 mm. The Japanese oak silkworm, A. yamamai Guerin, is an
oak-feeding, wild and semidomesticated species in Japan. In the forests the
caterpillars are watched on the native trees day and night until the cocoons are
gathered. The silk is of very fine quality. The species was also reared for some
years in Europe but, as in the case of all of these wild species, has been superseded
by the common Chinese or mulberry silkworm.
The largest silk-producing moth is the Atlas moth, Attacus atlas (Linn.),
which is not only one of the largest 1 lepidopterans but also one of the largest
insects known if we consider actual surface area. The females may attain a
wing expanse of 270 mm. (10!1; in.). The color varies from buff almost to
blackish-red, marked with white and various shades of tan, brown, black, and
red. The huge caterpillars are somewhat pulverulent and feed on a number of
plants as barberry, cinnamon, willow, Falconia, Milnea, apple, hornbean, etc.
They spin thick gray cocoons which are open at one end. The silk has been
used for many purposes. The species occurs throughout southern Asia and
Malaysia.
The ailanthus silkworm, Philosamia cynthia (Drury), and the race known as
the arrindy silkworm, P. ricini (Boisduval), is the most important of the wild
and semidomesticated species. It was very extensively utilized in its native
home in China, India, Japan, and the East Indies, and was naturalized in
Europe in 1861 and later in North America and Africa. The adults are olive
and reddish-brown, have an expanse of 136-144 mm. The larvre are green with
black and blue tubercles and feed chiefly on ailanthus, castor bean, keseru,
gulancha, gamari, and ber and to some extent also on barberry, wild cherry,
laburnum, and lilac. From 75-90 pounds of leaf are required to make 1 pound
of silk. In North America the species is established along the Atlantic coast.
This moth has entered very extensively into the bulky literature on sericulture.
The only native silkworm of value in South America is Rathschildia aurota
(Cramer), the silk of which was used extensively in northern South America.
from Brazil to Columbia, but the species ranges northward into Mexico. The
goree or deomuga silkwonll, Theophila religios;e (Helfer) (= huttoni Westwood).
is a wild species feeding on Machilus and Ficus in India. It is a large
silkworm, the caterpillars attaining a length of 6!1; in. being greatly exceeded
in size by the Atlas moth. The caterpillars are beautifully colored, and the
cocoons, which are 3 by 1!1; in., are constructed of a'coarse, strong silk used'
chiefly for making fishing lines.
l Attacus edwardsi White of AUstralia and Coscinoscera hercules Miskin of Australia and
Papua are about the same sille as this species but are not so well known. .