HYBERNATION OF INSECTS. 519 



necessarily pass the winter in that state, as those of several Anobia and 

 other wood-boring insects ; of Semasia Wceberana and others of the same 

 family ; of the second broods of several butterflies, &c. Many of these 

 residing in the ground, or in the interior of trees, need no other hyber- 

 nacula than the holes which they constantly inhabit ; some, as the aquatic 

 larvae, merely hide themselves in the sides or muddy bottom of their native 

 pools ; while others seek for a retreat under moss, dead leaves, stones, 

 and the bark of decaying trees. Most of these can boast of no better 

 winter quarters than a simple unfurnished hole or cavity ; but a few, more 

 provident of comfort, prepare themselves an artificial habitation. With 

 this view the larva of Cossus ligniperda, as formerly observed in describing 

 the habitations of insects, forms a covering of pieces of wood lined with 

 fine silk ; those of Hepiolus Humuli, Xyllna radicea, and some other moths, 

 excavate under a stone a cavity exactly the size of their bodies, to which 

 they give all round a coating of silk 1 ; and the larvae of Pieris Crattsgi in- 

 close themselves in autumn in cases of the same material 2 , and thus pass 

 the cold season, in small societies of from two to twelve, under a common 

 covering formed of leaves. Bonnet mentions a trait of the cleanliness of 

 these insects which is almost ludicrous. He observed in one of these 

 nests a sort of sack containing nothing but grains of excrement ; and a 

 friend assured him that he had seen one of these caterpillars partly pro- 

 trude itself out of its case, the hind feet first, to eject a similar grain ; so 

 that it would seem the society have on their establishment a scavenger, 

 whose business it is to sweep the streets and convey the rejectamenta to 

 one grand repository! 3 This, however singular, is rendered not impro- 

 bable from the fact that beavers dig in their habitations holes solely destined 

 for a like purpose 4 , as also do badgers. 



A very considerable number of insects hybernate in the perfect state, 

 chiefly of the orders Coleoptera, Hemiptera, Hymenoptera, and Diptera, and 

 especially of the first. Vanessa Urticce, lo, and a few other lepidopterous 

 species, with a small proportion of the other orders, occasionally survive 

 the winter ; but the bulk of these are rarely found to hybernate as perfect 

 insects. Of coleopterous insects, Schmid, to whom we are indebted for 

 some valuable remarks on the present subject 5 , says that he never found 

 or heard of any entomologist finding a hybernating individual of the com- 

 mon cock-chafer (Melolontha vulgaris), or of the stag-beetle (Lucanus 

 Cervus) ; and suggests that it is only those insects which exist but a short 

 period as larvae, as most of the tribes of weevils, lady-birds, &c., that sur- 

 vive the winter in the perfect state ; while those which live more than one 

 year in the larva state, as the species just mentioned, are deprived of this 

 privilege. 



i Brahm. 7ns. Kcd. ii. 59. 118. 



* I have reason to think that the larvae of some species of Hemerolius thus pro- 

 tect themselves by a net-like case of silken threads ; at least I found one to-day 

 (December 3rd, 1816) inclosed in a case of this description concealed under the bark 

 of a tree ; and it is not very likely that it could be a cocoon, both because the in- 

 habitant was not a pupa, which state, according to Reaumur, is assumed soon after 

 the cocoon is fabricated (iii. 385.), and because the same author describes the cocoons 

 of these insects as perfectly spherical and of a very close texture (384,), while this 

 was oblong, and the net-work with rather wide meshes. 



3 (Euv. ii. 72. * Ibid, ix. 167, 



5 Illig. Mag. i. 209228. 



L L 4 



