CHAPTER V. 



ASSOCIATIONS AND MIGRATIONS OF LEPIDOPTEROUS 



INSECTS. 



IN quadrupeds, birds, and fishes, there are instances 

 of extraordinary periodical migrations, principally 

 for the purpose of obtaining food in more abundance, 

 when it becomes scarce, from the effects of climate 

 or other circumstances. In insects, too, there are 

 frequent extensive migrations, to account for which 

 we find some difficulty. It is easy to see the reason 

 why some species of caterpillars associate, as they, 

 for their mutual protection, construct nests wherein 

 to retire, both during night and in bad weather. 

 The Papilio lo and canixia are examples of this : the 

 former constructs a nest like the Processionary Moth, 

 although differing in some particulars. 



Some insects associate only in their imago state ; 

 while others are gregarious in both conditions. 

 Others, again, congregate while in their larvae form ; 

 which, with a very few exceptions, is the case with 

 the numerous tribe of lepidopterous insects. These 



