The Pine Moth’s eggs hatch in September. If one lifts the scales of the little muff, one can see black heads appear, which nibble and push back their coverings. The tiny creatures come out slowly all over the surface. They are pale yellow, with a black head twice as large as their body. The first thing they do is to eat the pine-needles on which their nest was placed; then they fall to on the near-by needles.
From time to time, three or four who have eaten as much as they want fall into line and walk in step in a little procession. This is practice for the coming processions. If I disturb them, they sway the front half of their bodies and wag their heads.
“When winter is near they will build a stronger tent.”
The next thing they do is to spin a little tent at the place where their nest was. The tent is a small ball made of gauze, supported on some leaves. Inside it the Caterpillars take a rest during the hottest part of the day. In the afternoon they leave this shelter and start feeding again.
In less than an hour, you see, after coming from the egg, the young Caterpillar shows what he can do. He eats leaves, he forms processions, and he spins tents.
In twenty-four hours the little tent has become as large as a hazel-nut, and in two weeks it is the size of an apple. But it is still only a temporary summer tent. When winter is near, they will build a stronger one. In the meantime, the Caterpillars eat the leaves around which their tent is stretched. Their house gives them at the same time board and lodging. This is a good arrangement, because it saves them from going out, and they are so young and so tiny that it is dangerous for them to go out yet awhile.
When this tent gives way, owing to the Caterpillars having nibbled the leaves supporting it, the family moves on, like the Arabs, and erects a new tent higher up on the pine-tree. Sometimes they reach the very top of the tree.
In the meantime the Caterpillars have changed their dress. They now wear six little bright red patches on their backs, surrounded with scarlet bristles. In the midst of these red patches are specks of gold. The hairs on their sides and underneath are whitish.
In November they begin to build their winter tent high up in the pine at the tip of a bough. They surround the leaves at the end of the bough with a network of silk. Leaves and silk together are stronger than silk alone. By the time it is finished it is as large as a half-gallon measure and about the shape of an egg, with a sheath over the supporting branch. In the center of the nest is a milk-white mass of thickly-woven threads mingled with green leaves. At the top are round openings, the doors of the house, through which the Caterpillars go in and out. There is a sort of veranda on top made of threads stretched from the tips of the leaves projecting from the dome, where the Caterpillars come and doze in the sun, heaped one upon the other, with rounded backs. The threads above are an awning, to keep the sun from being too warm for them.