HYBERNATION OF INSECTS. 445 
cannot, at least in our climate, strictly be said to hy- 
bernate, understanding by that term passing the win- 
ter in one selected situation in a greater or less degree 
of torpor, without food. Not to mention Phalena 
G. brumata, and some other moths, which are disclosed 
from the pupze 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 eat. This is 
‘the case with the larva of Noctua fuliginosa, L.*; and 
Lyonet asserts that there are many other caterpillars 
which eat and grow even in the midst of slight frost®. 
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 Psychoda, so common in windows, several 
Muscide, spiders, and occasionally some Aphodi and 
Staphylintde : 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 1s 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 
a Brahm, Zns. Kal. ii. 31. b Lesser, D. i. 255. 
¢ See above, p. 4. 372. 
