442 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
about 14, inch in length, and are colorless until the embryos develop. 
They are deposited on the undersides of the leaves, usually singly or 
in small groups (Collins, 98). 
The partly grown sluglike larva is shaped somewhat like a dumb- 
bell, the central area being a little constricted, and the ends from which 
long spiny tubercles arise are enlarged. When full grown it 1s about 
7 inch in length, and has markings ‘of yellow, blue, green, and purple, 
the upper sur face having a dumbbell- shaped purple area which is en- 
larged over the extremities. The coloring, together with the long 
spiny tubercles, presents a very striking appearance. The cocoon 
is gray brown, sometimes mar ked with white, is about 14 inch in 
length, elliptical, smooth, and hard, and is firmly attached on one side 
to the bark of a twig, branch, or crotch. The pupa is light brown. 
The oriental moth is a native of Asia and was accidentally intro- 
duced into the United States, probably on nursery stock, sometime 
prior to 1906, when it was found in the Dorchester district of Boston, 
Mass. It is now firmly established but known to occur only in eastern 
Massachusetts. It has been intercepted at other points of entry on 
foreign nursery stock. Norway maple, sycamore maple, buckthorn, 
black birch, wild and cultivated cherry, apple, pear, and plum are 
most favored as food plants in its present range. When abundant 
it is known to feed on other maples, oak, aspen, willow, honeylocust, 
hickory, and hackberry. 
In Massachusetts there is one generation annually. The moth issues 
by forcing off a circular lid from the upper end of the cocoon late in 
June or July, and is active at night. The eggs hatch in about a week. 
The larvae at first feed on the lower epidermis of the leaves, but during 
later instars they eat all but the large veins. Larvae may become full 
grown in about 5 weeks, but str agglers are found until the first of Octo- 
ber. Each forms its cocoon by spinning a network of threads around 
itself and attaching them to the bark. It then continues from within 
to spin more silk and apparently secretes a liquid which fills the 
spaces between the threads and hardens. The larva passes the winter 
in its cocoon and transforms to a pupa about the first week of May. In 
confinement, a moth has laid as many as 551 eggs, and dissections of 
other females indicate that some may lay nearly 1,000 eggs. In addi- 
tion to its being a defoliator of shade, ornamental, and fruit trees, 
it is obnoxious because of the severe irritation people suffer when 
they come in contact with the larval spines. 
Among its natural enemies, Chaetexorista javana B. & B.,a parasitic 
fly was introduced from the Orient in 1929 and 1930, and is exerting a 
considerable influence in the control of this pest. Cocoons are some- 
times attacked during the winter by squirrels. 
Famity MEGALOPYGIDAE 
The Flannel Moths, or Puss Caterpillars 
The Iegalopygidae is a small family of stout-bodied moths which 
have long crinkly hairs on the wings, body, and legs. They have a 
wing expanse up to 114 inches, and the males are usually somewhat 
smaller than the females. The eggs are laid in small batches, usually 
on leaves, and are packed or covered with hairs from the abdomen 
of the female. The full-grown larva ranges from 34 inch to 1144 
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