486 THE BUTTERFLIES OF NEW ENGLAND. 



depressed ; the straight antennae are then spread at an angle of ninety 

 degrees and lie in the plane of the bod}'-, or perhaps slightly elevated. 



Enemies. As regards the parasites, Trogus exesorins (88:3) has 

 been bred from caterpillars of this insect by Mimdt, and Prof. A. E. Ver- 

 rill has reared a species of Apanteles, A. carduicola. Mr. Riley has also 

 bred a dipterous parasite, Exorista blanda (89 : 11) ; its larva usually issues 

 from the victim while the latter is in the caterpillar state, though some- 

 times not until it has transformed to chrysalis ; and in one instance the 

 Vanessa completed its metamorphoses with the parasitic fly yet in its abdo- 

 men ; it did not, however, properly expand its wings. I have seen this 

 s])ecimen and it is indeed a curious one ; all the appendages of head and 

 thorax were perfectly developed to their full capacity, but the wings only 

 expanded slightly beyond their pupal dimensions, though with all the 

 markino-s complete. The appendages of the abdomen (male) are abnor- 

 mally protruded, and the abdomen itself is completely depressed. Mr. 

 Riley has also bred Ichneumon rufiventris Brulle (88 : 1) from this insect ; 

 this hymenopteron issues from the anterior extremity of the chrysalis, in- 

 fested specimens of which may always be recognized by their pale color. 

 ]SIrs. Heustis of Nova Scotia found more than half of her chrysalids one 

 summer attacked by this parasite ; as well as she could judge (some 

 changes transpiring in the night) all the caterpillars which were attacked 

 were black, and all their chrysalids bright golden. Finally Mr. Riley has 

 notes of an egg-parasite, but no specimens are at hand. 



In Europe, the caterpillar is infested by a Microgaster ; some reared 

 by me perforated the skin of the caterpillar August 19th and made their 

 cocoons on its body. September 4th both dead and living imagines were 

 found, belonging to two distinct species, those of the smaller being dead 

 and dry, those of the larger either living or recently dead ; on the suc- 

 ceedino- day the remainder of the larger ones appeared, and proved to be, 

 as identified by my friend Mr. Drewsen, of Copenhagen, Microgaster sub- 

 completus var. ? von Esenb., and the smaller an undetermined species of 

 the same o-enus, probably undescribed. Of the former three males and 

 fifteen females emerged ; of the latter eight males and three females ; 

 besides these, four larvae had been taken from their cocoons and preserved 

 in that state ; all of these came from the body of a single caterpillar. 

 The laro-er species is probably the actual parasite of V. cardui ; the latter, 

 parasitic on the parasite. Besides these it is attacked in Europe accord- 

 ino- to Bignell and Ratzeburg by a Pimpla, a Limneria, a Bracon and an 

 Apanteles ; and Dr. Williston tells me that a species of Tachina is also 

 parasitic upon it, — making a total in Europe and America of ten hymen- 

 opterous and two dipterous parasites. Gentry states that he has found this 

 butterfly in the stomachs of the night hawk, Chordeiles virginianus, both 

 old and young, and in those of the chimney swallow, Chaetura pelagica. 



