Bntojwlogical Contributions. 137 



below: beneatli these is a row of black" pencils above a blue line 

 which incloses the stigmata. On segment ten is a similar arrange- 

 ment of pencils, bnt tlie twQ posterior ones are white instead of orange. 

 On segment eleven a double, dorsal black pencil from the two 

 anterior tubercles, two white ones posterior to these, and two black 

 ones exterior. On segment twelve are four black pencils directed 

 backward. The two lower rows of tubercles on segments one and 

 three, and the three rows on four and five, have fascicular bunches of 

 short white hairs radiating from them, as have also the corresponding 

 tubercles on the three posterior segments. The lower row of tuber- 

 cles on segments six to nine inclusive, have a few similar hairs 

 proceeding from their lower portion. Body of the larva, pale brown. 

 Legs shining black ; prolegs fuscous exteriorly. 



On August 1st, another molting occurred. On the 3d, from one 

 of the larvae, seyeral parasites emerged, and enclosed themselves in 

 small white cocoons of a slight texture, enveloped in loose wool-like 

 threads : from these seven hymenopterous imagines of an undetermined 

 species (all females) were disclosed on the 18th. 



On the Irtli, one of the larvge had spun its cocoon, through the 

 walls of which some parasitic larvae emerged. By the 9th, several 

 had made their cocoons,^ and all had ceased feeding. The last of the 

 colony made its cocoon on the 12th. 



On the 26th of August, an ^'gle imago emerged from one of the 

 CGCocns, which proved to be the only one obtained from the entire 

 colony. Late in the ensuing spring the cocoons were examined, 

 when about half of the number were found to contain untrans- 

 formed shriveled larvae, and the remainder dead pupae. 



Other attempts to rear broods of this larvae, have been attended 

 with about the same success, showing it to be a very difficult species 

 to carry through to the imago state, under treatment which proves 

 successful with many others. 



On the 21:th of August, — a month later than the date of collection 

 above noticed — another colony of this larva which had apparently 

 very recently undergone the first molting was observed feeding on 

 Asclepias. 



