MEANS OF DEFENCE OF CATERPILLARS. 193 



selves a snug- nest of silk, such as the caterpillars of 

 the brown-tail moth (Porthesia aurifliid), and those 

 of ihr. mallow-butterfly {Heaperia malv^). But there 

 are others which are provided with no extraneous 

 covering, farther than the occasional shelter they 

 may obtain by crawling under withered leaves, the 

 copings of walls, or the bend of a branch. Among 

 these some are thickly covered with hair, of which 

 we have an instance in the caterpillar of the great 

 tiger-moth {Arctiacaja, Stephens), whose mode of 

 rolling itself up into a ball we have already described; 

 but a more remarkable example occurs in the cater- 

 pillar of the drinker-moth {Odo?iestis potatoria, 

 Germar.), whose very feet are covered with fine 

 shaggy down. It is this, no doubt, which preserves 

 it from becoming" torpid during winter; and as it 

 feeds on grass, it can always procure food during 

 the severest weather. When a fine sunny day chances 

 to break in upon the gloom of winter, this pretty 

 insect may be often seen stretched at its full length 

 on a low twig, or the withered stem of a nettle, 

 basking in the sunshine with apparent delight. We 

 kept one of them in our study during the winter of 

 1827-8 ; and it continued to feed sparingly till Febru- 

 ary, when, owing to neglect, it unfortunately died*. 



There are several other caterpillars, however, 

 which live during the winter, in a no less exposed 

 manner, without being provided with any covering of 

 hair; though some of these, we may remark, do not 

 cot)tinue to feed, but become wholly or partially tor- 

 pid, such as the caterpillar of the magpie-moth 

 {Abraxas grossulariata). Of this species we have 

 observed numbers, about as thick as a crow-quill, 

 remaining in the same position for weeks together, and 

 never moving, except when some very considerable 

 change of temperature, either colder or hotter, took 

 place. They do not seem to select the warmest places 

 * J. R. 



