THE TRIBE OF THE ANGLE-WINGS 181 



grub state. By this time the caterpillar has become slug- 

 gish from the effects of the parasite. If the branch upon 

 which it feeds is disturbed, the other caterpillars are 

 likely to crawl away, but the enfeebled 

 victim remains in its place. 



Shortly after becoming full grown, 

 the Tachinid grub breaks through the 

 skin of the dying caterpillar and, fall- 

 ing to the ground, changes to a pecuhar "^^lughuy m^lt^!^.) '• 

 pupa; the outer skin of the grub turns 

 brown and becomes hard, forming a protective covering 

 for the body inside. A week or two later the insect 

 undergoes another change and emerges as a two- winged 

 Tachinid fly, like the one that laid the egg some weeks 

 before. 



Other Enemies 



Besides those insects that develop on the inside of the 

 bodies of these Antiopa caterpillars there are other 

 insect enemies which attack them from the outside and 

 devour them bodily. The most notable of these, perhaps, 

 is a large beetle commonly called the Caterpillar Hunter; 

 it is known to entomologists as Calosoma scrutator. This 

 is a very active insect, with large strong jaws, that runs 

 rapidly about in search of victims. In some cases it 

 has been observed while destroying many of the Antiopa 

 larvae. 



In the Southern states a common reddish wasp — a spe- 

 cies of Polistes — has also been observed attacking these 

 caterpillars, and there are probably various other insects 

 that destroy them, although definite observations show- 

 ing this have not been recorded. 



