INSECTS MISTAKEN FOR ALETIA. 
347 
are almost indistinguishable from those of Aletia, both being of the 
same size and of the same pale color. The former may, however, be at 
once recognized by the first and second pairs of prologs being entirely 
obsolete, whereas, notwithstanding their minute size, the second pair 
is always present in Aletia. In this stage the larva} are most active 
and nervous, and are usually found feeding on the lower side of the 
leaves, which they resemble so much in color that it is difficult to detect 
them when at rest. 
"They stretch to their fullest length when resting, but very often 
may be seen in a position similar to that of the larva? of Geometrids, 
and will then, if disturbed, leap from their hold and hang suspended by 
a thread, which, after a short rest, they will climb with great rapidity. 
The mode of climbing is very interesting. The head is suddenly bent 
downward, first to one side and then to the other, and each time the 
thread is grasped with the thoracic legs when the head is lowest. Grow- 
ing large]-, they become more and more sluggish, and can seldom be 
induced to spin, but usually hold to the leaf very tenacrously, so that 
some force is needed to remove them, if disturbed they will try to 
escape in a looping gait which is similar to that of Aletia. The full- 
grown larva' usually assume a very peculiar position when at rest. The 
body is bent at about the middle in such a way that both halves lie close 
to each other 80 88 to form a long and narrow loop, and the larva re- 
mains in this position sometimes for hours. 
"The principal time of feeding, as observed in the vivarium, appears 
to be at night, and the larva usually rests during the day on the lower 
side of the leaves. The smaller larwe eat only the softer parts, leaving 
the ribs untouched, but the older ones gnaw large irregular portions 
from the edge of the leaves, and will often consume two thirds of a leaf 
in a single night. They also have the habit of devouring their own cast 
skins, sometimes not even leaving the head, and the newly-hatched 
worms will frequently feed upon the empty egg-shells before attacking 
the leaf. We have in one instance, however, observed a young larva 
which had only partly issued from the egg already at work gnawing 
the leaf. 
u In March last [1882J we still found the larva* of all sizes on the 
Urena around Crescent City, Fla., but failed to find any trace of them 
on any other plant. This has also been the experience of Messrs. Neal 
and Hubbard, who were instructed to make observations on this point. 
i4 The moth (Plate II, Fig. 3) was first figured by Hubner (Zutr., 287, 
288), and is fully described under the name of Cosmophila crosa* by 
Guenee, who describes the larva in a few words and gives its food plant 
as Hibiscus. It occurs in South America, the specimens from Brazil 
being darker and brighter than ours, according to Guenee. The many 
Specimens we have bred and captured show comparatively little varia- 
tion. The color of the basal half of the front wing is bright yellow, 
*Hist. Geu. d, Ius. Lep., Noctu61ites, II. i>. 395. 
