336 IMPERFECT SOCIETIES OF INSECTS. 



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

 provision wiiicli it covers, they construct a new one over other roots of 

 this phint ; 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 (Porthesia 

 chrysorrhoen) before mentioned, whose caterpillars are of this description. 

 They belong to that family of Bomhycida which envelop their eggs in 

 hair plucked from their own body. As soon as one of these young cater- 

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

 it, placing itself by its side; thus they proceed in succession till a file is 

 formed across the leaf: — a second is then begun ; and after this is com- 

 pleted, 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 remainder 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 first is only a vaulted web, that 

 covers the leaf they inhabit, but by their united labors 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 cater- 

 pillars, 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 opinion, 

 that they are the parents of these caterpillars.^ 



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.^ 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 {Thedn Isocroics), 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 which it feeds. The 



I Reaumur, ii. 125. " De Geer, ii. 1029. 



