40 OUR SHADE TREES AND THEIR INSECT DEFOLIATORS. 
tawny-yellow front thighs, and blackish feet; in some specimens the 
tawny thighs have a large black spot, while the shanks on the upper . 
surface are rufous. In many all the thighs are tawny yellow, while in 
others they have scarcely any color. Some specimens (often reared 
from the same lot of larve) have two tolerably distinct spots on each 
front wing—one at base of fork on the costal nerve and one just within 
the second fureation of the median nerve. Other specimens, again, 
have their wings spotted all over, and approach the form punctatissima, 
described as the “ Many-spotted Ermine-moth” of the Southern States. 
The wings of the moths expand from 1} inches to 14 inches. The male. 
moth, which is usually a little smaller, has its antennz doubly feath- 
ered beneath, and those of the female possess-instead two rows of 
minute teeth. 
‘¢ The pupa state lasts from six to eight days for the summer brood, 
while the hibernating brood, however, requires as many months, ac- 
cording to the Jatitude in which they occur. 
INJURY DONE IN 1886. 
‘¢ During the past year the city of Washington, as well as its vicinity, 
was entirely overrun by the caterpillars. With the exception of trees 
and plants the foliage of which was not agreeable to the taste of this 
insect, all vegetation suffered greatly. The appended list of trees, 
shrubs, and other plants shows that comparatively few kinds escaped 
entirely. The fine rows of shade trees which grace all the streets and 
avenues appeared leafless, and covered with throngs of the hairy worms. 
Excepting on the very tall trees, in which the highest branches showed 
a few leaves too high for the caterpillars to reach, not a vestige of foliage 
could be seen. The trees were not alone bare, but were still more dis- 
figured by old and new webs made by the caterpillars, in which bits of 
leaves and leaf-stems, as well as the dried frass, had collected, produc- 
ing avery unpleasant sight. The pavements were also constantly coy- 
ered with this unsightly frass, and the empty skins of the various 
molts the caterpillars had to undergo were drifted about with every 
wind, and collected in masses in corners and tree-boxes. The parks 
fared alittle better. Because of the great variety of trees planted there 
some escaped entirely, while others showed the effect of the united 
efforts of so many hungry caterpillars only in a more or less severe 
degree. The grassy spots surrounding the different groups of trees had 
also a protective influence, since the caterpillars do not like to travel 
over grass, except when prompted by a too ravenous hunger. The rapid 
increase of this insect is materially assisted by the peculiar method of 
selecting shade trees for the city. Each street has, in many cases, but 
one kind of shade tree; rows of them extend for miles, and the trees 
are planted so close together that their branches almost interlace. Thus 
there is no obstacle at all to the rapid increase and distribution of 
