DISTRIBUTION AND FOOD PLANTS. 
The tent caterpillar is a native American species occurring quite 
generally in the United States from Canada south to Florida and 
westward about to the Rocky Mountains. From the Rockies to the 
Sierras, according to Dyar, the species is replaced by Jlalacosoma 
fragilis Stretch, which ranges from Canada to Mexico, and this lat- 
ter form in the Pacific Northwest is replaced by MZalacosoma plu- 
vialis Dyar. 
The tent caterpillar has been a troublesome pest from the earliest 
times. As stated by Fitch, its injuries in Massachusetts in the 
years 1646 and 1649 led the early settlers to term these “ caterpillar 
years.” At rather long and irregular intervals the caterpillars have 
been excessively abundant in different parts of their range, but more 
particularly in the New England States. This species was among 
the first to receive attention by the early American entomologists, 
and the principal features in its life and habits have been known for 
many years. Throughout its extended distribution the insect is 
likely to be abundant each year in one or more localities and often 
over a considerable territory. Scattered nests are to be found usu- 
ally during any spring, though during some seasons these are but 
little in evidence. 
The favorite food of the tent caterpillar is the wild cherry, and 
this is probably its native food plant. Next to the wild cherry the 
apple is apparently preferred. In the absence of its favorite food, 
or under special conditions, it attacks many other plants, as plum, 
peach, thorn, pear, rose, and other members of this group; also 
beech, witch-hazel, elm, maple, various species of willows, oaks, and 
poplars, etc. During periods of unusual abundance trees are more 
or Jess completely defoliated, and at a time when they most need the 
leaves for their growth or for the development of the fruit, and they 
are materially weakened, though rarely killed. 
DESCRIPTION AND LIFE HISTORY. 
The egg—Kggs are deposited in masses or belts encircling the 
smaller twigs, as shown in fig. 2, and at @, fig. 1. Different egg masses 
may vary from one-half to three-fourths of an inch in length and 
contain from 150 to 250 eggs. The average number of eggs in several 
ege masses counted by Prof. V. H. Lowe on peach and apple was 
about 223 each. Each egg belt is deposited by an individual female 
and ordinarily represents the entire number which she will deposit. 
Eges are placed on end, cemented closely together, the whole oval- 
shaped mass being finally covered with a layer of light-brown frothy 
glue, which soon becomes tough, brittle, and glistening. 
[Cir. 98] 
