520 HYBERNATION OF IXSECTS. 



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. I 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 



every 



semblage, with the addition of multitudes of other beetles, Halticce, Niti- 

 dul(B, 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 antennae 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 of 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, 1. 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 together, as his translator erroneously understands 

 him ; but merely that they assemble as if preparing to retire for the winter, which 

 my own observations, as above, confirm. His expression in the original German is, 

 " gleichsam als wenn sie sich zu ihrer Winter-rune fertig machen wolten." Edit. 

 Frankfurt und Leipsig, 1738, p. 152. 



