16 



Similar work is done in the last stage upon the full-grown and tough 

 leaves (see fig. 7). 



A most peculiar kind of damage by the caterpillars of this species 

 has been observed by Dr. Lintner in Albany, N. Y. There, in the 

 summer of 1883, he found that the tips of many twigs were girdled 

 by the caterpillars, which had entirely removed the bark for a tenth 

 of an inch. Such twigs broke off and fell to the ground, with their 

 leaves. This damage was so common in 1883 that the sidewalks of 

 the streets and public parks wherever the American elm was growing 

 were sprinkled with. the newly fallen leaves. Dr. Lintner was of the 

 opinion that a cold spring and the sudden advent of warm weather 

 caused an unusually vigorous growth of the terminal twigs, and that 

 the young tips were therefore unusually tender. They thus proved 



Fig. 6.— Tussock-moth caterpillar. First, second, and third stages— enlarged (original). 



appetizing to the tussock-moth caterpillars, which developed a liew 

 habit for the occasion. This peculiar damage was repeated in 1895, 

 but to a less extent. No other observer in any part of the country 

 has ever reported similar damage. 



The young caterpillars drop down, suspended by silken threads, at 

 even a slight jarring of the tree, and frequently spin down without 

 such disturbance, and are blown to a considerable distance by the 

 wind. When nearly full grown they are great travelers, crawling 

 down the trunk of the tree upon which they were hatched and across 

 a considerable stretch of ground, to ascend another tree. When they 

 occur in numbers, an extensive migration will always take place from 

 a tree which has been nearly defoliated, and the species spreads mainly, 

 if not entirely, in this way. Just as is the case with the gypsy moth, 



