20 BRITISH BUTTERFLIES. 



larvae wander far off until they do so for pupation, but they cease to 

 go to and fro so much, and so, though still spinning silk to walk upon, 

 do not increase the considerable webs spun during the early stages. As in 

 the Palaaarctic, so in the Nearctic, region, the habits of the larvae of 

 Euvanessa an tiopa make it the outstanding gregarious species of the butter- 

 fly fauna, and Scudder says (Butts. New England,,!., pp. 404, 673) of this: 

 "Perhaps, of all our caterpillars, although it constructs but a slender 

 web, Euvanessa antiopa is the most pre-eminently social. The eggs 

 are laid in a cluster of greater or smaller size around a terminal twig, 

 which the larvae leave together, and, as if by common impulse, range 

 themselves side by side in compact rows along a chosen leaf, t!heir 

 heads always thereafter remaining together at the edge of the eaten 

 leaf. Even if they are separated forcibly from each other they come 

 together again and rearrange themselves. When disturbed, they will 

 simultaneously strike an attitude of alarm and turn their heads in 

 unison, as if worked by a machine. They spin a thin web, which 

 Meyer-Dur has compared with that spun by the larvas of the European 

 Lachneis lanestris, enclosing the whole twig, but not the leaves upon 

 which they are feeding, nor ever leave this carpet nest until the branch 

 is stripped of its leaves, when they move to a neighbouring twig. The 

 web they form is thus simply that which they make as they crawl 

 about, each following hurriedly in the track of its predecessor, and as 

 it moves adding its thread to the carpet upon which it treads. They 

 are generally found high up in the tree and remain social throughout 

 the larval life .... Their progress on a tree may sometimes be 

 traced by the clusters of cast-off skins they have left in their track, the 

 first on a leaf-rib, the others on a stem of one of the twigs, for they 

 crowd together at the time of ecdysis as at others, and, as they undergo 

 their changes, at least the earlier ones, at nearly the same time, the 

 clusters of cast-off skins (which they never eat) remain to mark 

 the steps of their progress. When the caterpillars have finished a 

 repast they retire to the stripped twigs and leaf-stalks for a siesta, 

 where they place themselves, almost invariably, head downwards, and 

 remain almost immovable for a long while, the head and first thoracic 

 segment a little raised, so that the front pair of legs is lifted from the 

 twig and directed forwards, while the body hangs from the other legs 

 and prolegs which thus have a backward direction." Harrison notes 

 (Ins. inj. Veg., 3rd ed., p. 297) that "he has seen the lame sometimes 

 in such profusion on willows and elms that the limbs bend under their 

 weight, and the long leafless branches which they had stripped and 

 deserted gave sufficient proof of the voracity of these caterpillars." 

 [We doubt very much the limbs of any elm bending under the weight 

 of these larvas.] 



Katzeburg notes (Die Forstinsecten, pp. 71-72) that the young larvas 

 of Eugonia polychloros cover the whole of the area traversed from the 

 eggs from which they have hatched to their feeding-place, with white 

 web, that the distance is slowly increased, and that, by the time they 

 have moulted the first time, they have spun several leaves together, 

 leaving the cast skins on the web. Directly after this moult (June 

 4th, 1839) a batch under observation divided into two lots, which 

 went their separate ways on different branches. The members of 

 each division remained associated until the end of June or the 

 beginning of July, when the mass of larvae hung like bunches of 



