FAMILY HABITS IN BUTTERFLY LARViE THE FRITILLARIES. 31 



in the Palaearctic, region, merely a matter of the nature of the season, 

 weather, altitude, or latitude. Prittwitz's remarkable guess, quoted 

 by Scudder (op. cit., p. 607), that Brenthis thore only flies in alternate 

 years, appears to be absurd, the larva of this species, like those of 

 B. selene, B. euphrosyne, etc., having almost identical family habits (see 

 Ent. Bee, xviii., p. 69), only that, even less than B. euphrosyne, there 

 appear to be no "forward " larva? to form a partial double-brood. 



Possibly no family of butterflies shows more marked family larval 

 characters than the Melitaeids. It is unfortunate that some of the 

 absolute knowledge one would like does not appear to be available 

 concerning the non-British, but European, species. Still, of those 

 that are known, the uniformity of the family larval traits is sufficiently 

 remarkable. These are exhibited in (1) their abundant silk-spinning- 

 habits in their earliest stadia ; (2) the gregarious habits of the young 

 larvae up to, and including, hybernation ; (3) the social hybernation in 

 a fixed stadium, usually the third (or fourth); (4) the tendency to 

 solitary life after hybernation ; (5) the lethargic habits accompanying 

 the assumption of cryptic habits after hybernation ; (6) the thorough- 

 ness of the hybernating rest. We are unfortunate in not having very 

 reliable data concerning many of the habits of the larvag of the 

 Palaearctic species, but, so far as our three British species — Melitaea 

 aurinia, M. athalia, and M. cinxia — are concerned, they are remark- 

 ably similar in most of their habits in the larval stage, e.g., they spin 

 silk freely, are quite social in early life, hybernate crowded in a 

 common web, all hybernate, we believe, in the third stadium, 

 distribute themselves considerably directly after the first moult after 

 hybernation, are then lethargic in their movements, and trust rather 

 to cryptic effects in relation to their surroundings for protection, than 

 hiding away. This latter trait does not imply the inability of the 

 larvae to travel rapidly, which they can do if necessity arises. All this 

 seems to be equally true of the larvae of Melitaea didyma, M. parthenie, 

 M. dictynna, and possibly others. In America, the habits of the 

 Melitaeids are very similar, and Scudder writes (Butts. New England, 

 i., p. 619) that "the eggs are generally (perhaps always) laid in 

 clusters, and the caterpillars, at least in the early half of their lives, 

 are social, often constructing common webs, in which some kinds 

 hybernate, for, as far as is known, all the species of this tribe, whether 

 in the New World or the Old, pass the winter as halfgrown cater- 

 pillars." The larvae of Phyciodes tharos, however, are described as 

 " social," without spinning any web, and at the time of hybernation 

 leaving the foodplant to hide in crevices of the ground (op. cit., 

 p. 638). Similarly, the larvae of Charidryas nycteis are said (op. cit., 

 p. 664), to be gregarious when young, feeding only on the parenchyma 

 of the leaves, leaving only a transparent membrane, but not con- 

 structing any web for concealment or protection, hybernating, also 

 without spinning any protective covering, possibly in crevices, etc. It 

 may be well here to notice that, according to Wilde, the larvae of 

 M. maturna are social until the time of hybernation, living in webs, 

 after the fashion of M. aurinia, M. cinxia, etc., on Fraxinus excelsior, 

 but that, in the third stadium, they leave the tree for hybernation, 

 going down to the ground, hiding among leaves, etc., apparently 

 without spinning web of any description, and remaining solitary after 

 they recommence feeding in the spring. 



