THE CATERPILLAR AND THE MOTH
some terrible dream or as if pursued by a demon, hurries outward along a branch, goes to the end of a spur or the tip of a leaf, and without slackening continues into space till the end of the support tickles his stomach, when suddenly he gives a flip into the air, turns a somersault, and lands on the ground (Fig. 150).
The first performance of this sort was observed on May 15 in the Connecticut colonies. On the afternoon of the 19th, twenty or more caterpillars from two neighboring colonies were seen leaving the trees in the same fashion within half an hour. Most of the members of one of these colonies had their last molt on May 12 and 13. During the next few days other caterpillars were observed jumping from four trees containing colonies under observation. All of these went off individually at various times, but most of them early in the afternoon. Many caterpillars simply drop off when they reach the end of the branch, without the acrobatic touch, but only three were seen to go down the trunk of a tree in commonplace style.
The population of the tents gradually decreases during several days following the time when the first caterpillar departs. One of the two tents from which the general exodus was noted on May 19 was opened on the 21st and was found to contain only one remaining caterpillar. On the evening of the 22nd a solitary individual was out feeding from the other tent. The two younger colonies maintained their numbers until the 22nd, after which they diminished till, within a few days, their tents also were deserted. The members of all these colonies hatched from the eggs on April 8, 9, and 10, so seven weeks is the greatest length of time that any of them spent on the trees of their birth. The caterpillar that left the tent on the 15th came from a colony that began to hatch on April 10, giving an observed minimum of thirty-six days.
After the mature caterpillars leave the tents, they wander at large and feed wherever they find suitable
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