18 BRITISH BUTTERFLIES. 



April 2nd, 1900, he received a quantity of M. aurinia larvae, from 

 Cumberland, just out after hybernation. They all came out and 

 basked in the sunshine as usual, but, after a few days, about 5 per 

 cent, spun fresh webs, and went inside, and although he tried to force 

 these to feed up under glass, it was of no use. They refused to leave 

 the web until March, 1901, when they fed up in the usual way. On 

 another occasion he had the same experience, but as there were only 

 some five or six larvae involved, he did not trouble to keep them. 

 Wilde says (Stett. Ent. Zeitg., xx., p. 381) that, he found, near Zeitz, 

 on several young trees of Fraxinus excelsior, webs, which contained multi- 

 tudes of small larvae of M. maturna ; the larvae went down to the 

 ground, at the end of September, when about Jin. long, and in spring 

 were found up again, feeding on the ash. No remark, however, is 

 made as to whether they hybernate gregariously or have any social 

 habits in the spring. Gillmer says (in litt.) that M. cynthia larvae 

 hybernate in common webs. 



Scudder says (Butts. New England, i., p. 673) that, as far as 

 the New England fauna is concerned, the great mass of social 

 caterpillars are found in the Nymphalids, which includes, of course, 

 the Vanessids and Melitaeids. Outside these two groups, however, 

 the Nearctic fauna presents us with another characteristic gregarious 

 species, viz., Chlorippe clyton, an Apaturid, that lays its eggs in 

 large dense clusters of from 200-500, in two, or often three, and 

 sometimes even four or five, tiers. Edwards says (Can. Ent., xvi., 

 p. 87) that the larvae of the autumn broods of Chlorippe clyton and C. 

 celtis hybernate after the third moult and gather in dense clusters on 

 the underside of the leaves of their foodplant, as close as they can pack. 

 On September 21st, he found 165 larvae of C. clyton so collected on one 

 leaf. These Apaturids are unprotected by any webs. Of the larvae of C. 

 clyton, Scudder writes (Butts. New England, p. 245) : "They are gregari- 

 ious during the first three stages, ' feeding side by side, eating the leaf 

 from the tip downward, but leaving the stouter ribs. Spinning a thread 

 wherever they go, they often, in travelling from leaf to leaf, make 

 quite a pathway of silk ; and, if the pathway be suddenly jarred, they 

 will drop and hang suspended in mid- air, and after reassurance climb 

 up again with the thoracic legs ' (Riley). In thus feeding together, 

 they completely conceal the leaf, according to Edwards, but do not, as 

 in many gregarious larvae, ' rest with heads all turned the same way 

 and bodies in line and parallel . . . . but form an irregular 

 mass, the heads mostly outside and fronting in every direction.' . . 

 . . After the third moult and when about halfgrown, hybernation 

 commences ; the larvae cluster upon the leaves and fall with them to 

 the ground, and, in spring, make their way again from the ground to 

 the tree." The gregarious habit here noticed is very like that of the 

 Vanessids, in which the larval web is undoubtedly, especially after the 

 second stage, merely a means of keeping up a satisfactory connection 

 between the various parts of the gregarious company, and seems to be 

 little used for the purpose of hiding, and, in this respect, the gregarious 

 habit is much more complete in the larvae of the tree-feeding Eugonia 

 nolychloros and Euvanessa antiopa than in those of the allied species 

 Vanessa io and Aglais nrticae (see Nat. Hist. Brit. Butts., vol. i., pp. 

 57-58). There is no need to repeat an account of the gre- 

 garious habits of the larvae of A. nrticae, already fully dealt 



