THE OAK-EGGER MOTH — THE PUSS MOTH. 499 



the pupal state has been achieved. In the present example, the 

 larva has permitted the cocoon to be made, and then killed the 

 caterpillar, the reason of this delay being that the cocoon is very 

 firm and strong, and affords an' impregnable shelter to the para- 

 site. The names of the Parasites are placed beneath the cocoons. 



Within the same case there are several cocoons in which a 

 similar calamity has befallen the caterpillars which made them. 

 There is, for example, a cocoon of the Oak-egger Moth (Lasio- 

 campa quercas), the interior of which resembles that of the insect 

 which has just been described, except that the cells of the parasite 

 are more numerous. This species of caterpillar is peculiarly sub- 

 ject to the attacks of the ichneumon flies, as is well known to all 

 practical entomologists, who lose many of their carefully-bred 

 specimens by means of these insects. 



There is also one of the winter cocoons of the Goat Moth cat- 

 erpillar, the inmate of which has been pierced by the ichneumon 

 fly, and killed by its young. As the species of ichneumon is a 

 large one, only a single individual was produced, and, as may be 

 seen from the cell of the parasite which is placed by the side of 

 its victim, the habitation of the ichneumon is so large that it must 

 have occupied nearly the entire cocoon of the dead caterpillar. 



In another room, placed among the series of British moths, is a 

 cocoon of a Puss Moth (Centra vinula) which has been occupied 

 by two ichneumon larvae. 



If the reader should happen to know the cocoon of this moth, 

 he will remember that it is made of wood scrapings, glued togeth- 

 er with a cement secreted by the insect, and that its walls are so 

 hard that a tolerably strong knife is required in order to cut it 

 open. That the eggs of a parasite should be introduced into the 

 body of the larva is not an extraordinary circumstance, but that 

 the perfect insects should be able to make their way out of such 

 a cocoon is really wonderful. The interior of this cell is hard 

 and smooth as if made of polished ebony, and its concavity ren- 

 ders it more difficult of penetration. Yet these singular insects 

 contrive to make their way through the sturdy walls. 



The ichneumons which usually attack the Puss Moth are rath- 

 er large insects, belonging to the genus Ophion, and have long, 

 i slender, curved abdomens, and long antennas slightly twisted at 

 the ends. The color is orange, diversified with black. Those 



