NOCTUAS. 



245 



are hatched in October ; the little CATEE- 

 PILLAB, on leaving the egg-shell, being per- 

 fectly black and very hairy : they appear 

 to hybernate in the crevices of the stone 

 while still extremely small, but in the 

 following March or February, or even the 

 end of January, if the weather happen to 

 be wet and mild, they again begin to feed : 

 each then constructs a new house for him- 

 self, a kind of cocoon made of silk and 

 particles of earth, mortar, or stone ; this 

 cocoon has little resemblance to the usual 

 formula adopted by caterpillars when pre- 

 paring for pupation, but is very like the 

 blister we occasionally see on paint ; while 

 tenanted, it is closed at both extremities, 

 just as though the occupant had shut him- 

 self up to undergo pupation ; in the night 

 or early morning, more especially in wet 

 weather, he gnaws an opening at one end 

 of his dwelling-place, comes completely 

 out, and feeds on the lichen ; but during 

 the greater part of the day, and indeed 

 during the night also in very dry weather, 

 he remains shut up in his house : in moist 

 weather, after making a copious meal on 

 the saturated and swollen lichen, each 

 caterpillar seeks his accustomed shelter, 

 always carefully fastening the door, or, in 

 other words, spinning up the opening ; but 

 it is curious, and rather opposed to the 

 ordinary habits of insects in this respect, 

 that, as a general rule, each caterpillar is 

 totally careless whether he return to his 

 own dwelling-place or to that of some 

 friend or relation : he will, without a mo- 

 ment's hesitation, coolly possess himself of 

 any tenement he finds unoccupied, and 

 carefully closing the entrance, maintain 

 his position against all comers ; supposing, 

 however, that the tenement he examines 

 with a view of taking possession be already 

 cc-cupied, he never presumes to intrude, 

 never thinks of contesting the point, but 

 continues to wander about on the look-out 

 for a house until he finds one unoccupied : 

 an occupied cell is invariably closed, so that 

 when you find one open, you may at once 

 conclude it is an empty house ; in no in- 

 stance do two caterpillars attempt to occupy 

 the same dwelling as tenants in common. 

 Should any difficulty arise in finding an 



empty house, which not unfrequently hap- 

 pens, the caterpillar sets to work in the 

 most contented manner to construct one, 

 and probably before long is as comfortably 

 housed as any of his friends. I have said 

 that in dry weather these caterpillars re- 

 main sealed up in their domiciles, and when 

 this continues for long, they appear to suffer 

 greatly from lack of food for if, after a 

 long continuance of drought, the cocoon be 

 forcibly opened, the caterpillar is found in 

 a very shrivelled and atrophied state, with 

 its head disproportionately large and con- 

 spicuous. When full-fed, which is about 

 the end of May, it has a limp and flaccid 

 character very similar to that of a cater- 

 pillar that has been ichneumoned ; it 

 neither feigns death nor rolls in a ring 

 when disturbed or annoyed, as probably 

 the only protection it seeks or requires is 

 that afforded by its case. The head of the 

 full-grown caterpillar is porrected in crawl- 

 ing ; it is rather narrower than the body, 

 and is perfectly glabrous, but emits about 

 thirty fine hairs, which are directed for- 

 wards ; the body is of uniform substance 

 throughout, the back slightly depressed, 

 the belly flattened ; each segment has twelve 

 warts, and each wart emits a bristle. The 

 colour of the head is intense black and 

 shining, the labrum white ; the dorsal sur- 

 face of the body is dark smoke-coloured as 

 far as the spiracles, and having an irregular 

 narrow medio-dorsal yellowish stripe, in- 

 terrupted on the tenth, eleventh, and twelfth 

 segments ; the warts and bristles are white, 

 the ventral surface beginning at the spira- 

 cles, as also the legs and claspers are 

 ochreous -yellow ; in very wet weather, when 

 the caterpillar feeds voraciously, the belly 

 and all the under parts assume a tinge of 

 green : nevertheless, although these parts 

 assume this green tinge after voracious 

 feeding, they invariably return to their 

 normal colour before pupation, thus proving 

 the altered tinge to be the result of reple- 

 tion; when the time of pupation arrives, 

 they usually secrete themselves in holes in 

 the wall, and spin a slight web among old 

 spiders' webs, dust, and crumbled earth or 

 mortar, in which they undergo the change, 

 but sometimes they use for this purpose 



