NY.MPIIALIXAE: EUVANESSA ANTIOPA. 405 



the branch is stripped of its leaves, when they remove to a neighboring 

 twig. They are generally found high up in the tree and remain social 

 throughout their caterpillar life ; for, although the leaves of the trees on 

 w^hich they feed cannot support a row of the full-grown caterpillars, they 

 are still found in the closest possible proximity, following each other's 

 footsteps, the branches upon which they arc clustered borne down by their 

 united weight. 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 these 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 

 downward and remain immovable for a long wiiile, their head and first 

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

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

 and prolegs which thus have a backward direction. 



Mr. T. G. Gentry gives the following picture of the occasional abundance 

 of this insect, the caterpillars of which were being attacked by a large 

 beetle : — 



Although the destruction was on a singularly grand scale, yet hundreds of larvae 

 remained to undergo their ti-ausforraations during the latter part of August. The 

 eaves of the buildings, . . . fence rails, and in sliort nearly every available place, were 

 hung with the angular chrysalides. So numerous were the latter, that after the final 

 metamorphoses had passed, the red fluid which was ejected by the tender and newly 

 formed butterflies gave everything the appearance of having been profusely spattered 

 with blood. The area subjected to the desolating influence of these larvae did not 

 cover less than two acres of ground. (Proc. acad. nat. sc. Philad., 1875, 24.) 



Dr. Harris says of this caterpillar (Ins. inj. veg., 3d ed., 297) : — 



It was formerly supposed that they were venomous and capable of inflicting dan- 

 gerous wounds ; and within my remembrance many persons were so much alarmed on 

 this account as to cut down all the poplar trees around their dwellings. This alarm 

 was unfounded ; for although there are some caterpillars that have the power of inflict- 

 ing venomous wounds with their spines and hairs, this is not the case with those of the 

 antiopa butterfly*. The only injury which can be laid to their charge is that of despoiling 

 of their foliage some of our most ornamental trees, and this is enough to induce us to 

 take all proper measures for exterminating the insects, short of destroying the trees 

 that they infest. I have sometimes seen them in such profusion on the willow and 

 elm that the limbs bent under their weight and the long, leafless branches which they 

 had stripped and deserted gave suflicient proof of the voracity of these caterpillars." 



Dr. Kirtland also says : " The larva, which often feeds on the foliage 

 of the lombardy poplar, excited strong prejudice some years since against 

 such trees, from an erroneous belief that the tenant was venomous, like 



*Harris elsewhere says that the species of able to experience any sensation from con- 

 this caterpillar irritate the skin, but I have tact with them, more than any pointed ob- 

 experimented directly and have never been jeet would give. 



