440 HYBERNATION OF INSECTS. 



ter in one selected situation in a greater or less degree 

 of torpor, without food. Not to mention Cheimatobia 

 britmata, and some other moths, which are disclosed 

 from the pupae in the middle of winter, and can there- 

 fore be scarcely regarded as exceptions to the rule, 

 some insects are torpid only in very severe weather, and 

 on fine mild days in winter come out to e.at. This is 

 the case with the larva of Euprepia fuliginosa a ; and 

 Lyonet asserts that there are many other caterpillars 

 which eat and grow even in the midst of slight frost b . 

 Amongst perfect insects, troops of Trichocera hiemalis, 

 the gnat whose choral dances have been before described , 

 may be constantly seen gamboling in the air in the 

 depth of winter when it is mild and calm, accompanied 

 by the little P&ychoda^ so common in windows, several 

 Muscida, spiders, and occasionally some Aphodii and 

 Staphylinidce : and the societies of ants, as well as their 

 attendant Aphides, are in motion and take more or less 

 food during the whole of that season when the cold' is 

 not intense. The younger Huber informs us that ants 

 become torpid only at 2 Reaum. below freezing (27 

 Fahrenheit), and apparently endeavour to preserve them- 

 selves from the cold, when its approach is gradual, by 

 clustering together. When the temperature is above 

 this point they follow their ordinary habits (he has seen 

 them even walk upon the snow), and can then obtain 

 the little food which they require in winter from their 

 cows the Aphides, which, by an admirable provision, 

 become lethargic at precisely the same degree of cold as 

 the ants, and awake at the same period with them d . 



a Brahm, Ins. Kal ii. 31. b Lesser, L. i. 255. 



c See above, p. 4. 375. 



d Reckcrchcs, 202. In digging in my garden on the 26'th of Janu- 



