THE WHITE-SPOTTED TUSSOCK MOTH. 
263 
towns, parks, gardens, and orchards than iu forests. As this insect has 
recently been studied by Professor Riley and his assistants, I repro- 
duce their results: 
The eggs. — During the month of June, and more especially late in fall and through- 
out the winter, glistening white objects may be seen on the trunks and "the larger 
branches of trees, or in the corners of the fences near by, or on bunches of dead leaves 
hanging on the tree (see Fig. 102 a). Upon examination these masses will be found 
to be ghied on to a cocoon of dirty gray color, and to consist of numerous perfectly 
round, cream-white eggs, which are partly covered by a glistening white froth or 
a b c 
Fig. 102. — Orgyia leucostigma: a, female ou cocoon; 6, larva; c, female pupa; d, male pupa; e, male. 
Riley del. 
spittle-like matter. In one of these egg-masses which we received from Kansas we 
have counted as many as 786 eggs, while from another mass we obtained upward 
of 400 young caterpillars. 
The young caterpillars scatter all over the tree soon after hatchiug. When dis- 
turbed they make free use of a fine silken thread, which they spin, and by which 
they let themselves down. The full-grown larvae are ofcen seen to change quarters 
and travel from one branch to another or from one tree to another. Their rather 
quiet way of moving contrasts strongly with the nervous movements of the Fall 
Web-worm. 
In the latitude of St. Louis, Mo., and Washington, the eggs begin to hatch about 
the middle of May, and the newly-born caterpillar, not quite 3 millimeters in length, 
is of dull whitish-gray color, with the under side paler, the upper side being covered 
with rather long hairs and tufts of a dark-brown color. In two days from hatching 
small orange spots begin to appear along the back, and ou the seventh day the first 
Fig. 103.— Orgyia leucostigma : female caterpillar. Riley del. 
molt takes place, to be followed at intervals of six days each by the second and third 
molts. The changes that take place during this time in the appearance of the cater- 
pillar are remarkable, and after the third molt it is a beautiful object and of striking 
appearance (Fig. 103). 
Larva. — The head and two little elevated spots situated on joints 9 and- 10 are 
bright vermilion red; the back is velvety black with two bright yellow subdorsal 
lines, and another yellow line each side along the lower sides. The whole body is 
thinly clothed with long pale-yellow hairs, originating from small wart-like eleva- 
tions. Four cream-colored or white dense brushes of hair are in a row ou the middle 
