IX. 



NESTS AND OTHER STRUCTURES MADE BY 

 CATERPILLARS 



There is considerable difference among the 

 cater]3illars of butterflies as to the amount of silk 

 they spin. Some, and this is especially true of 

 the Lycaenidae, and next of the Pierinae, spin very 

 little and have apparently little use for it, being 

 able to make their way about without weaving a 

 carpet whereon to cling, though they ordinarily 

 do spin some. Others seem unable to take a 

 single step without laboriously spinning a thread 

 wherever they would go, fastening it upon this side 

 and that, and without it will venture nowhere. 

 As a general rule nests of any sort are constructed 

 only by the last-named, i. e. by those most depend- 

 ent upon a hold on silken strands to make their 

 way. Yet there is one notable exception in a 

 Mexican Pierid which constructs a web nearly as 

 close as parchment. 



Nests, which are almost solely for purposes of 



J 



