INSECTS MISTAKEN FOR ALETIA. 347 



are almost iDdistinguishable 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 prolegs being entirely 

 obsolete, whereas, notwithstanding their minute size, the second pair 

 is always present in Aletia. In this stage the larvsB 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 larvae 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 w^ith the thoracic legs when the head is lowest. Grow- 

 ing larger, they become more and more sluggish, and can seldom be 

 induced to spin, but usually hold to the leaf very tenaciously, 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 larvae 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 so as 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 larvae 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 ui>on 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. 



"In March last [1882] we still found the larvae 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. IsTeal 

 and Hubbard, who were instructed to make observations on this point. 



"The moth (Plate II, Fig. 3) was first figured by Hubner (Zutr., 287, 

 288), and is fully described under the name of Cosmophila erosa* by 

 Guenee, who describes the larva in a few words and gives its food plant 

 as Eihiscus. It occurG 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. Gen. d. lus. L6p., Noctu61ites, II, p. 395. 



