460 HABITATIONS OF INSECTS. 



Various substances besides silk are fabricated into ha- 

 bitations by other larvae, though usually joined together 

 either with silk or an analogous gummy material. Thus 

 Diurnea ? Lichenum forms of pieces of lichen a dwelling 

 resembling one of the turreted Helices, many of which I 

 observed in June 1812 on an oak in Barham. The lar- 

 vae of another moth, which also feeds upon lichens, in- 

 stead of employing these vegetables in forming its habi- 

 tation, composes it of grains of stone eroded from the 

 walls of buildings upon which its food is found, and con- 

 nected by a silken cement. These insects were the sub- 

 ject of a paper in the Memoirs of the French Academy 3 , 

 by M. de la Voye, who, from the circumstance of their 

 being found in great abundance on mouldering walls, at- 

 tributed to them the power of eating stone, and regarded 

 them as the authors of injuries proceeding solely from 

 the hand of time : for the insects themselves are so mi- 

 nute, and the coating of grains of stone composing their 

 cases is so trifling, that Reaumur observes they could 

 scarcely make any perceptible impression on a wall from 

 which they had procured materials for ages b . Another 

 lepidopterous larva, but of a much larger size and diffe- 

 rent genus, the case of which is preserved in the cabinet 

 of the President of the Linnean Society, who pointed it 

 out to me, employs the spines apparently of some spe- 

 cies of Mimosa, which are ranged side by side so as to 

 form a very elegant fluted cylinder. A similar arrange- 

 ment of pieces of small twigs is observable in the habita- 

 tion vof the females of the larvae of a moth referred by 



a x. 458. b Reaum. iii. 183. 



The larvae of the males intermix with the pieces of twigs, which 

 are less closely and regularly arranged, bits of dried leaves and other 

 light materials. See the excellent elucidation of the history of this 

 tribe, whose mode of generation is so singular, by Von Scheven, 



