606 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



covered with compound spines ; two ou each side of the second segment black, pro- 

 ceeding from a red wart ; two on each side of the third segment, the main stem being 

 red at base, yellow at extremity, and those proceeding from it being black. On all the 

 other segments but the last two (ou each side of which there are two compound black 

 spines) there are seven, three on each side and one on the back. That on the back is 

 yellow and smaller than the rest ; those nearest this are also yellow, but with black 

 extremities, particularly toward the head; those below these last have a red stalk 

 with black spines proceeding from it, and those along the sbigmatal line (which line 

 is very light yellow) are of the same color as that line and very small. Two lines run 

 along the back, closest together near the spines and having the appearance of a 

 succession of links. There are also other lines running parallel with these, but not 

 so distinct, along the sides. Head perpendicular, free, larger than the body, very 

 dark purple-brown, and covered sparsely with small white points from which proceed 

 fine white bristles ; on the top it has two black compound spines. Thoracic legs same 

 color as head, the prolegs of a lighter brown. Length, IJ inches; diameter, one-fifth 

 inch. 



It hangs by the cremaster and anal prolegs* to a small bunch of 

 flesh-colored silk, and changes to a chrysalis similar in form to others 

 of its group, of a fleshy-brown color shaded with bluish-black. It has 

 a crescent-shaped projection on the thorax, with four golden spots just 

 below. The wing-sheaths are faintly green, having a slight resem- 

 blance to a leaf. 



Some specimens of the larva are much brighter than others, being 

 speckled or mottled all over with white, and the chrysalis, instead of 

 having four golden, has often four brilliant, silvery, metallic spots, 

 while the whole body may be tinted with gold and green, particularly 

 along the stigmata. 



Mr. Scudder says : 



Judging from the dates given by Harris's correspondence, the chrysalis state lasts 

 from eleven to seventeen days. Grosse (Canada) says eleven days. Edwards (iu 

 West Virginia), seven to eleven. Braun, in Bangor, had ihem hang twenty days at 

 the end of July. 



My specimens at St. Louis remained nine days, on the average, in 

 the chrsyalis state, which is most frequent in July, while the butter- 

 flies are most numerous in August. The butterfly, therefore, appears 

 iu Missouri about the same time as in the New England States, viz, 

 from the last of July to the middle of August, and is probably but 

 two-brooded. 



Parasites. — Two parasites are found in the eggs, Telenomus graptce 

 Howard, reared at Washington, and Trichogramma intermedium How- 

 ard, reared by Mr. Scudder at Cambridge. An undescribed Apanteles 

 and Pteromalus vanessw Harris are quite frequently reared, the one from 

 the larva, the other from the chrysalis. Tetrastichus modestus Howard 

 is a secondary parasite on the Apanteles, while a large Ichneumonid, 

 Hoplismenus morulus Say, was once reared from it by Miss Pierce at 

 Cambridge, all recorded in Mr. Scudder's work. 



*See a paper by the author on the "Philosophy of the pupation of Butterflies," Proc. 

 Am. Ass. Adv. Sc, for 1879, vol. 28, pp. 455-463. 



