53 



In the apartment containing those Army Worms which had none 

 of the Tacliina eggs attached to them, the moths issued as follows : 



August 6, one; August 8, three; August 10, seven; and August 

 11, nine. 



Altogether twenty moths issued in this apartment. These did not 

 issue from the chrysalis at any stated hour, but the greater number 

 issued a short time before sunset. When I examined them at half- 

 past six o'clock in the afternoon of August 8, one of the moths had 

 just issued from the chrysalis. 



In this apartment I placed twenty-eight of the Army Worms. In 

 an examination which I made of this apartment on the 19th of 

 August, I found it to contain four Army Worm chrysalids and one 

 larva and one pupa of a Tachina-fly ! Here, then, was an Army 

 Worm infested by this parasite, and yet showing no signs that it 

 was thus infested ! 



In this case the parent fly had probably attached two of its eggs 

 to the body of one of the Army Worms before the latter had cast 

 its skin for the last time, and when the skin had been cast off the 

 eggs, remaining attached to it, were also thrown off, not, however, 

 before the larvae or maggots had hatched out and entered the Army 

 Worm's body. 



Assuming that this larva and pupa had infested the body of only 

 one Army Worm, there were then only three of these worms in this 

 apartment that could not be accounted for, and these had probably 

 died before pupating. 



On the 29th of July I found in the above apartment a few larvae, 

 or maggots, and a great many pupae of the Red-tailed Tachina-fly 

 (Exorista leucania, Kirkpatrick*). The maggots measure about three- 

 eighths of an inch in length, are of a pale yellowish color, and the 

 body tapers anteriorly; the posterior end terminates abruptly, and 

 is somewhat truncated ; near the upper edge of the truncation are 

 two nearly circular, blackish-brown spots, placed transversely. The 

 jaws are black, and are bent downward at the tips ; they are prob- 

 ably used more as organs of attachment or of locomotion than of 

 nutrition, as the maggot is legless ; and it is very probable that it 

 obtains its nourishment by absortion through the skin. It does not 

 spin a cocoon before assuming the pupa form, neither does it cast 

 its skin before assuming this form, but its body contracts into an 

 oblong-elliptical pupa of a blackish or brownish color, and measuring 

 nearly three-eighths of an inch in length. Some of the pupae are 

 shaped like a cylinder which has rounded ends, and many of them 

 are much smaller than the measurement given above. 



In the apartment which contained the Army Worms on whose 

 bodies one or more Tachina eggs were attached, the Tachina-flies 

 issued as follows : 



August 5, one ; August 6, eight ; August 8, twenty-six ; August 9, 

 eleven; August 10, five flies and three Army Worm Moths; August 

 11, five ; August 12, one ; and August 13, one. 



I examined this apartment August 19, and found in it three dead 

 Tachina-flies, forty-three pupae of these flies, and one Army Worm 

 chrysalis. This apartment originally contained sixty-three Army 



* This fly is now placed in the genus Memorece, and is identical with the Senometopia 

 militaris, of Walsh. 



