116 MOTHS AND BUTTERFLIES. 
which spring from tubercles on its sides and back. With each moult 
the caterpillar grows lighter, and when fully grown is two inches 
long, dull yellowish in color, with a curved horn somewhat resem- 
bling that of the larva of a sphinx moth on the posterior end, and 
the first three segments next the head very much swollen and 
wrinkled. The interior of the body is filled largely with the silk 
glands, extending one on either side in a loosely-wrinkled tube. 
These are the glands from which, after the larva is steeped in vine- 
gar, the silk gut so useful to the angler is manufactured. The 
cocoons are often very beautiful and symmetrical, usually oval, but 
sometimes constricted slightly about the middle. They are ordinarily 
light yellow, though sometimes silvery white, greenish or flesh color. 
The moths emerge in about three weeks. They are cream colored 
with two indistinct lines across the fore wings, and as they expand 
only a little over an inch, are small in proportion to the size of the 
larva and the cocoon. Neither male nor female is able to fly, and 
after leaving the cocoons they pair, the females lay their eggs and 
soon die. 
This insect has been so long under cultivation that several varie- 
ties have been produced which, if found in a wild state, would be 
considered distinct species. The original wild stock is not known, 
but may yet be found in some of the little-known interior districts of 
China or India. 
An insect which is fast becoming well known through the United 
States and Canada through the efforts of the Massachusetts legis- 
lature in distributing profusely illustrated literature on the subject, 
is the Gypsy moth, Ocnerta or Porthetria dispar, an importation 
from Europe. The larva of this moth, to which little in the way of 
vegetation seems to come amiss, is a most destructive pest, and, but 
for the efforts of the state, which has appropriated large sums of 
money for its extermination, the insect would doubtless ere this have 
spread over the whole of the eastern half of Massachusetts. At 
present it is confined to a limited extent of country within Middlesex 
County, and it is hoped that by persistent effort it may be entirely 
eradicated. The insect is attacked at every stage of its development. 
About the trunks of trees in infected districts bands of burlap are 
secured, and under these the larve are often found resting during 
the day, they being night-feeders. The pupie concealed about stone 
walls, on fences and tree-trunks and like places, frequently in im- 
mense numbers, are destroyed when found. The ege clusters are 
