THE WHITE-MARKED ORGYIA. 
36T 
apple-trees are much infested by them, as was the case in 
the summer of 1828. In the summers of 1848, 1849, and 
1850, they were very numerous on trees in Boston, both in 
private yards and on the common, where the horse-chestnuts, 
which seem ordinarily to escape the attacks of insects, were 
almost entirely stripped of their leaves by these insects. 
When they have done eating, they spin their cocoons on the 
leaves, or on the branches or trunks of the trees, or on fences 
in the vicinity. The chrysalis is not only beset with little 
hairs or down, but has three oval clusters of brannv scales 
on the back. In about eleven davs after the change to the 
chrysalis is effected, the last transformation follows, and the 
insects come forth in the adult state, the females wingless, 
and the males with large ashen-gray wings, crossed by wavy 
darker bands on the upper pair, on Avhich, moreover, is a 
small black spot near the tip, and a minute white crescent 
near the outer hind angle. The bodv of the male is small 
and slender, with a row of little tufts along the back, and 
the wings expand one inch and three eighths. The females 
(Plate YII. Figs. 2 and 3) are of a lighter gray color than 
the males, their bodies are verv thick, and of an oblong oval 
shape, and, though seemingly wingless, upon close examina¬ 
tion two little scales, or stinted winglets, can be discovered 
on each shoulder. These females lay their eggs upon the 
top of their cocoons (Plate VII. Fig. 5), and cover them 
with a large quantity of frothy matter, which on drying 
becomes white and brittle. Different broods of these insects 
appear at various times in the course of the summer, but 
the greater number come to maturity and lay their eggs in 
the latter part of August and the beginning of September, 
and these eggs are not hatched till the folio win «• summer. 
The name of this moth is Orgyia * leucostigma (Plate YII. 
* This name is derived from a "word which signifies to stretch out the hands, 
and it is applied to this kind of moth on account of its resting with the fore legs 
extended. The Germans call these moths streckfdssige Spinner ; the French,/?a«es 
etendues; and the English, vaporer-moths; the latter probably because the males 
are seen flying about ostentatiously, or vaporing, by day, when most other moths 
keep concealed. 
