18 



IMPERFECT SOCIETIES OF INSECTS. 



their own balls, but an equal care for the whole appears to 

 affect all the community." 1 



Many larvae also of Lepidoptera associate with this view, 

 some of which are social only during part of their existence, 

 and others during the whole of it. The first of these continue 

 together while their united labours are beneficial to them ; 

 but when they reach a certain period of their life, they dis- 

 perse and become solitary. Of this kind are the caterpillars 

 of a little butterfly (Melitcea Cinxia) which devour the narrow- 

 leaved plaintain. The families of these, usually amounting 

 to about a hundred, unite to form a pyramidal silken tent, 

 containing several apartments, which is pitched over some of 

 the plants that constitute their food, and shelters them both 

 from the sun and the rain. When they have consumed the 

 provision which it covers, they construct a new one over 

 other roots of this plant ; and sometimes four or five of these 

 encampments may be seen within a foot or two of each other. 

 Against winter they weave and erect a stronger habitation of 

 a rounder form, not divided by any partitions, in which they 

 lie heaped one upon another, each being rolled up. About 

 April they separate, and continue solitary till they assume the 

 pupa. 



Reaumur, to whom I am indebted for this account, has 

 also given us an interesting history of another insect, the gold- 

 tail moth (Portliesia chrysoi^rhcea) before mentioned, whose ca- 

 terpillars are of this description. They belong to that family 

 of Bombycidce which envelop their eggs in hair plucked from 

 their own body. As soon as one of these young caterpillars 

 is disclosed from the egg it begins to feed ; another quickly 

 joins it, placing itself by its side; thus they proceed in suc- 

 cession till a file is formed across the leaf: — a second is then 

 begun ; and after this is completed, a third — and so they 

 proceed till the whole upper surface of the leaf is covered: — 

 but as a single leaf will not contain the whole family, the re- 

 mainder take their station upon the adjoining ones. No 

 sooner have they satisfied the cravings of hunger, than they 

 begin to think of erecting a common habitation, which at 



1 Catesby's Carolina, ii. 111. 



