IMPEKFECT SOCIETIES OF INSECTS. 



19 



first is only a vaulted web, that covers the leaf they inhabit, 

 but by their united labours as I have described in a former 

 letter in due time grows into a magnificent tent of silk, con- 

 taining various apartments sufficient to defend and shelter 

 them all from the attacks of enemies and the inclemency of 

 the seasons. As our caterpillars, like eastern monarchs, are 

 too delicate to adventure their feet upon the rough bark of 

 the tree upon which they feed, they lay a silken carpet over 

 every road and pathway leading to their palace, which extends 

 as far as they have occasion to go for food. To the habitation 

 just described they retreat during heavy rains, and when the 

 sun is too hot : — they likewise' pass part of the night in them; 

 — and, indeed, at all times some may usually be found at 

 home. Upon any sudden alarm they retreat to them for 

 safety, and also when they cast their skins : — in the winter 

 they are wholly confined to them, emerging again in the 

 spring : but in May and June they entirely desert them ; 

 and, losing all their love for society, live in solitude till they 

 become pupae, which takes place in about a month. When 

 they desert their nests, the spiders take possession of them ; 

 which has given rise to a prevalent though most absurd opi- 

 nion, that they are the parents of these caterpillars. 1 



With other caterpillars the association continues during 

 the whole of the larva state. De Geer mentions one of the 

 saw-flies (Serrifera) of this description which form a common 

 nidus by connecting leaves together with silken threads, each 

 larva moreover spinning a tube of the same material for its 

 own private apartment, in which it glides backwards and 

 forwards upon its back. 2 I have observed similar nidi in this 

 country ; the insects that form them belong to the Fabrician 

 genus Lyda. 



A small East Indian hair-streak butterfly ( Thecla Isocrates), 

 of whose economy Mr. Westwood has given an interesting 

 account, resides in the larva state in small societies of at least 

 seven or eight individuals in the inside of the pomegranate, 

 on the seeds and pulp of Avhich it feeds. The fruit being thus 

 rendered weak and unable to support its own weight would 



1 Reaumur, ii. 125. 



2 De Gcer, ii. 1029. 



C 2 ' 



