HYBERNATION OF INSECTS. 519 
necessarily pass the winter in that state, as those of several Anobia and 
other wood-boring insects ; of Semasia Waberana 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, Xylina 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!; and the larvae of Pieris Crategi in- 
close themselves in autumn in cases of the same material *, 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 conyey the rejectamenta to 
one grand repository!’ 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 Urtice, Io, 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 °, 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 (ucanus 
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. 
1 Brahm. Jns. Kal. ii. 59. 118. 
2 T have reason to think that the larva of some species of Hemerobius thus pro- 
tect themselves by a net-like case of silken threads; at least I found one to-day 
(December 8rd, 1816) inclosed in a case of this description concealed under the bark 
of atree; 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. 
5 (uv. ii, 72. 4 Thid. ix, 167, 
5 Illig. Mag. i, 209—228. 
Lu 4 
