528 PROCEEDINGS OF Till: NATIONAL MVSEl 1/ . vol.38. 



TRICHOSTIBAS ISTHMIELLA, new species. 



Labial palpi black. Tongue white. Face and head deep blackish 

 blue. Antennae dark blue. Thorax lighter, slaty blue. Forewings 

 dark violet, clouded with lighter, inky, bluish violet. The color 

 appears very nearly uniform under a lens, but in certain lights two 

 broad, ill-defined bands of the lighter color can be made out, one at 

 basal third, one at apical third, and the extreme tip is also somewhat 

 lighter. Cilia dull blackish blue. Ilindwings very dark, dull blackish 

 fuscous, darker than those of any of the other described species 

 and but very slightly transparent, just enough to distinguish the 

 still darker veins. Abdomen deep metallic blue; ovipositor long, 

 horny. Legs deep blue. Alar expanse, 37 mm. 



Ilabitat. — Gorgona, Canal Zone, Panama. E. A. M. Swaine, coll. 



Type.— Cat, No. 13151, U.S.N.M. 



A cocoon of this species with a live pupa was received through the 

 mails on April 16, and on the same day the moth, a female, issued. 



The cocoon is of the general open network type of the genus and 

 is apparently very similar to that of T. fumosa Zeller, described by 

 Lord Walsingham. A picture of similar cocoons is given without 

 identification of the species by Henry Edwards in The Standard 

 Natural History, vol. 2, 1SS4, p. 438. 



In the present species the cocoon is suspended from a leaf by a stiff, 

 silken thread more than 13 inches long, which, like the cocoon itself, 

 is of a bright salmon red color. This supporting thread divides into 

 three branches at the top of the cocoon, two of which form the edge 

 of the opening through which the moth issues, while the third is 

 continued along the one side of the cocoon, but does not protrude 

 beyond it as in the cocoon of our Florida species. These thick 

 threads are evidently spun first by the larva, which, suspended on 

 them in midair, makes the regular open network between them 

 and around itself. The cocoon is kidney-shaped, 19 by 10 mm., and 

 consists of heavier parallel threads about IV mm. apart, connected 

 bv thinner cross threads about 1 mm. apart and underlaid by an 

 irregular open network of very fine threads. The moth issues through 

 the hole at the upper end; at the lower end the cocoon terminates 

 in a short, open neck, through which the larval skin is pushed out 

 after pupation, thus insuring a clean, airy habitation, free from 

 anything that might become water-soaked, or by its smell attract 

 ants, the ever present enemy of other insect life in the Tropics. The 

 cnl ire elaborate contrivance is presumably a very effect ive protection 

 against ants dining the defenseless pupa period, for even should an 

 ant attempt to climb down the long suspending thread it would 



a Proc. /""I. Soc. London, is<»7, ]>. 1 1 1. 



