520 TIYBERNATION OF INSECTS. 
Towards the close of autumn the whole insect world, particularly the 
tribe of beetles, is in motion. A general migration takes place: the various 
species quit their usual haunts, and betake themselves in search of secure 
hybernacula. Different species, however, do not select precisely the same 
time for making this change of abode. Thus many lady-birds, field-bugs, 
and flies are found out of their winter quarters even after the commence. 
ment of frost; while others, as Schmid has remarked, make good their 
retreat long before any severe cold has been felt; in fact, I am led to 
believe, from my own observations, that this is the case with the majority 
of coleopterous insects; and that the days which they select for retiring 
to their hybernacula are some of the warmest days of autumn, when they 
may be seen in great numbers alighting on walls, rails, pathways, &c., and 
running into crevices and cracks, evidently in search of some object very 
different from those which ordinarily guide their movements. T have 
noticed this assemblage in different years, but more particularly in the 
autumn of 1816, Walking on the banks of the Humber on the 14th of 
October about noon, — the day bright, calm, and deliciously mild, Fahren- 
heit’s thermometer 58° in the shade,—my attention was first attracted by 
the pathways swarming with numerous species of rove-beetles (Staphylinus, 
Oxytelus, Aleochara, &e.), which kept incessantly alighting, and hurrying 
about in-every direction. On further examination I found a similar as- 
semblage, with the addition of multitudes of other beetles, Haltice, Niti- 
dule, Rhyncophora, Cryptophagi, &c., on every post and rail in my walk, as 
well as on a wall in the neighbourhood; and on removing the decaying 
mortar and bark, I found that some had already taken up their abode in 
holes, from their situation, with their antennz folded, evidently meant 
for winter quarters. I am not aware that any author has noticed this re- 
markable congregation of coleopterous insects previously to hybernating, 
which it is so difficult to explain on any of the received theories of 
torpidity, except the pious Lesser, who so expressly alludes to it, and 
without quoting any other authority, that he would seem to have derived 
the fact from his own observation,1 
The site chosen by different perfect insects for their hybernacula is very 
various. Some are content with insinuating themselves under any large 
stone, a collection of dead leaves, or the moss of the sheltered side cf an 
old wall or bank. Others prefer for a retreat the lichen or ivy-covered 
interstices of the bark of old trees, the decayed bark itself, especially that 
near the roots, or bury themselves deep in the rotten trunk ; and a very 
great number penetrate into the earth to the depth of several inches. The 
aquatic tribes, such as Dytisci, Hydrophili, &c., burrow into the mud of their 
pools ; but some of these are occasionally met with under stones, bark, 
&c, In every instance the selected dormitory is admirably adapted to the 
constitution, mode of life, and wants of the occupant, Those insects 
which can bear considerable cold without injury are careless of providing 
1 Lesser, I. i. 256. Lyonet inserts a note to explain that Lesser’s remark is to be 
understood only of such insects as live in societies; and adds, that solitary species 
do not assemble to pass the winter together. Lesser, however, says nothing about 
these insects passing the winter (ogether, as his translator erroneously understands 
him; but merely that they assemble as if prenieg to retire for the winter, which 
my own observations, as aboye, confirm, His expression in the original German is. 
“ gleichsam als wenn sie sich zu ihver Winter-ruhe fertig machen wolten.” Edit. 
Frankfurt und Leipsig, 1738, p. 152, 
