554 HYBERNATION OF INSECTS. 



&;c., that survive 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. 



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 

 commencement 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, path- 

 ways, &c., and running into crevices and cracks, evidently in search of 

 some object very different from those which ordinarily guide their move- 

 ments. I have noticed this assemblage in different years, but more par- 

 ticularly in the autumn of 1816. Walking on the banks of the Humber 

 on the 14th of October about noon, — the day bright, calm, and deli- 

 ciously mild, Fahrenheit's thermometer 58° in the shade, — my attention 

 was first attracted by the pathways swarming with nemerous species of 

 rove-beetles (^Staphylinus , Oxytelus, Aleochara, &;c.), which kept inces- 

 santly alighting, and hurrying about in every direction. On further 

 examination I found a similar assemblage, with the addition of multitudes 

 of other beetles, Halticce, JSitidulce, Rhyncophora, Cryptophagi, &c., on 

 every post and rail in my walk, as well as on a wall in the neighborhood ; 

 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 remarkable 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.^ 



The site chosen by difTerent perfect insects for their hybernacula is 

 very various. Some are content with insinuating themselves under any 

 lartre 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, espe- 

 cially 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 



1 Lesser, 1. i. 256. Lyonet inserts a note to explain that Lesser's remark is to be under- 

 stood only of such insects as live in societies ; and adds, that solitary species do not assem- 

 ble to pass tlie 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, con- 

 firm. His expression in the original German is, "gleichsam als wenn sie sich zu ihrer 

 winter-ruhe fertig machen wolten." Edit. Frankfurt und Leipsig, 1738, p. 152. 



