40 



STRUCTURE OF THE LEPIDOPTERA 



Although the caterpillars of this species do not show any great 

 gregarious tendency when nearly full fed, yet it is not an un- 

 common thing to find several hanging from the under surface of 

 one leaf, all being attached to the one common carpet at which all 

 had worked. And when bred in confinement, a number will often 

 spin in company in a corner of their cage. I have thus obtained a 

 cluster of thirty-seven pupae, all hanging by the ' tails ' to the 

 same mass of silk, which was so small that they formed quite a 

 compact mass of beings with their tails close 

 together. 



We have seen that the Large White Butter- 

 fly makes itself secure by a silk band round its 

 middle, while the ' Tortoiseshell ' is fixed only 

 by its tail. But the extra provision for the safety 

 of the former is not so necessary in the case of 

 the latter, as it never spends more than two or 



FIG. 28. THE COCOON OF THE 

 EMPEROR MOTH. 



FIG. 



29. THE COCOON 

 OF THE SIX-SPOTTED 

 BURNET (FilipendulcB). 



three weeks in the pupal state. Here it is the perfect insect that 

 braves the winter, and not the chrysalis. 



There is a great variety in the means taken by the caterpillars 

 of moths to protect themselves during their metamorphoses, but we 

 shall have space for only a few illustrations. 



A clever cocoon is spun by the larva of the Emperor Moth 

 (Pavonia). It is pear-shaped, and composed of a brownish silk ; 

 and is so constructed that the newly emerged moth can easily walk 

 out of the small end without breaking a fibre, while the entry of an 

 insect enemy from without is impossible. 



This is managed as follows. A number of rather stiff threads 

 are made to project from the small end of the cocoon, and these 

 converge as they pass outward so that the ends are all near 



