530 Notice of a Congregation of Moths 



maintenance of the common abode. But the possession of 

 these locomotive organs by insects which, nevertheless, remain 

 confined to a single " local habitation," although unfettered by 

 cares for a future offspring, indicates, as it appears, an equally 

 strong propensity towards sociality with the insects of the 

 former group : and this brings to our notice another feature 

 in the economy of these social species of insects; namely, that, 

 whilst the social principle is not exhibited by the insects of the 

 former group until their arrival at the imago state, it is ob- 

 served in the individuals of the latter group only during their 

 preparatory states. It must be borne in mind, however, when 

 treating of social insects, that there are many species which 

 are found in great swarms without any common tie. Thus 

 the vast armies of locusts, the sportive clouds of gnats and 

 midges, or the whirling assemblies of the Gyrinus natator, ex- 

 hibit a species of sociality, but of a very slight nature. Born 

 in the same locality, and having no other object than obtain- 

 ing a supply of food, or performing the great object of their 

 existence, these insects may be dismissed from our notice, as 

 may also the species composing the former group, of which 

 such ample details are given in those parts of the works of 

 Reaumur, Kirby and Spence, &c, which relate to the ants, 

 wasps, hive bees, humble bees, &c. 



Of the insects which associate together, in their prepara- 

 tory states, for the construction of a common abode, many 

 are of very common occurrence. The webs of the caterpillars 

 of the lackey moth (Clisiocampa Neustria) may be mentioned 

 as affording a good example of this kind of sociality. These 

 handsome caterpillars are very voracious, and the numbers of 

 individuals composing one of their assemblies contrive, in a 

 few days, to strip the branches of our fruit trees of their leaves. 

 They continue to reside in society, and to increase the size of 

 their nest until full grown : but here their sociality ceases ; 

 each departs, and selects a distant situation for undergoing 

 its change to the pupa state; and the same proceeding is 

 adopted by the majority of tent-making caterpillars, such as 

 the gold-tail moth (Porthesia chrysorrhae v a) and brown-tailed 

 moth (P. auriflua), &c. 



It is, however, of very rare occurrence, that, in this group 

 of social insects, the pupa? are gregarious ; or rather, perhaps, 

 more properly speaking, that the caterpillars do not, previously 

 to assuming the pupa state, quit the common abode. Reaumur, 

 indeed, tells us, in his account of the caterpillars of the 

 processionary moth, " C'est dans leur nid que ces chenilles 

 doivent perdre leur forme et devenir chrysalides ;" and that 



