THE AMEEICAN ENTOMOLOGIST. 



193 



projection, which has sometimes been lil^eued 

 to a Roman nose, glowing out of (lie middle of 

 its back. This projection, however, is not a 

 pecnliarity of this purticnlar species, hut oc- 

 curs in the pupic of all the species belonging to 

 this genus (Nymphnlis), the fraiisformatioiis of 

 which are known. 



The Disippus butterfly, as is correctly stated 

 by Harris, is double-brooded ; but that author 

 is entirely wrong in asserting that (he second 

 brood passes the winter in the pupa state.* He 

 l)robably jumped to this conclusion from finding 

 the butterfly flying abont so early in the spring- 

 that it could not have had sufficient time to 

 hatch out from the egg and acquire its full 

 larval growth the same season: and with its 

 wings so bright and unworn, that it could not 

 have hyberiiated in the butterfly form, as do 

 certain allied species {Vanessa Antiopu and 

 several species of Grapta) . The real truth of 

 the matter is, that the autumnal brood of larvas 

 have only attained about one-third their full 

 size when the winter sets in, and hybernate in 

 a singular house (Fig. 134 c), which they con- 

 struct for this purpose out of the leaf of the 

 willow. First and foremost — with wise fore- 

 thought, and being well aware through its natu- 

 ral instincts, that the leaf which it has selected 

 for its house will fall to the ground when the 

 cold weather sets in, unless it takes measures to 

 prevent this — the larva fasteus the stein of the 

 leaf with silken cables securely to the twig from 

 which it grows. It then gnaws otT the blade of 

 the leaf at its tip end, leaving nothing but the 

 mid-rib, as shown in Figure 134 d. Finally, it 

 rolls the remaining part of the blade of the leaf 

 into a cylinder, sewing the edges together with 

 silk, the gnawed portion of the leaf forming a 

 long flap which is bent down and fastened by 

 silken cords so as to act as a door to the house. 

 The basal portion of the cylinder is of course 

 tapered to a point, as the edges of. the leaf are 

 merely drawn together, not overlapped; and 

 invariably the lower side of the leaf forms the 

 outside of the house, so as to have its projecting 

 mid-rib out of the way of the larva, as it re- 

 poses snugly ill the inside. The whole when 

 flnished (Fig. 134 c), has somewhat the appear- 

 ance of the leaf of a miniature pilclier-plant 

 {Sarraceniu), its length being 0.50 — O.Co inch, 

 and its diameter 0.11 — 0.14 inch. 



We have found these winter-houses in the 

 summer time, old, dry and empty, on the 

 Heart-leaved AV^illow (Srdix corduta) ; and on 

 April 18lh, 18C.5, and for a week or two subse- 

 quently we found great numbers of recent ones 



• Injurious Insects, p. 282. 



on the Humble "Willow (8. IlumiKs), some few 

 of them still containing the larva, but most of 

 them empty and with the larva in the immedi- 

 ate neighborhood, crawling sluggishly about 

 and nibbling the catkins of this willow, which 

 were then in full flower but not yet in leaf. "We 

 placed a lot of these larvre in a breeding-cage 

 and fed them upon willow; and from this lot 

 we bred one pupa on May Tith, and four others 

 between that date and May 15th. The first but- 

 terfly appeared May 21st, and two afterwards 

 on May 24th. "We have also bred the butterfly 

 on August 16th, from a p.upa found in the open 

 air suspended from the stem of a grass-plant in 

 the woods, and of course belonging to the first 

 brood of larvaj.* 



No other American butterfly has hitherto been 

 recorded as liybernating in the larva state, and 

 this is the first complele account that has yet 

 been published of the singular mode in which 

 this process is accomplished by the larva of the 

 Disipjms butterfly. t Not the least wonderful 

 part of the phenomenon is, that it is only the 

 autumnal brood of larvte that form pitcher-like 

 houses to live in during the inclement season of 

 the year, the summer brood having no occasion 

 to shelter themselves from the cold. "We tiius 

 have an instance of a curious architectural in- 

 stinct being only developed in alternate genera- 

 tions; which is much the same thing as if, with 

 a certain race of men, the great-grandfathers, 

 the fathers and the grandchildren ran wild in 

 the woods, and the grandfathers, the sons and 

 the great-grandchildren lived in houses and led 

 the life of civilized human beings. 



•As there is do goorl ilcscription extiiut of this lurvii, we 

 :miiex uUeseriiitiou careliiUy clnuvu up from the exaiiiina- 

 tioii nf three living specimens. 



Cylimlrical, \.W inch imi^' ami 25 inch in diMiiieter. 

 CJeneral color whitish. Ileu.l .hill olive, with dense minnle 

 prickles; its vertex billd and terminating in a pair of prickly 

 cylindrical horns, transversely arrangeil and each ali'iiit 

 U.O.i inch long, liact speckled and mottled with olive of 

 diUerent shades above the line of the spiracles, except joints 

 2 and S and the upper part of 7 and 9, but with a confiinions 

 pure white line above the spiracles, beneath wliicli white 

 line on joints 4-10 is a large olive patch extending on joints 

 H-U to the external tip of the prologs A pair of black t lans- 

 versely-arranged dorsal dots in the suture behind joint 2, 

 and a less obvious lateral one above the 2nd and 4th pair of 

 prolegs surmounting the lateral white line. Joints :i-7 ami 

 9-11 with more or less, shinin,!,', elevated, blue dots. On 

 joint 2 a pair of prickly cylindrical black horns, transversely 

 arranged and O.lti inch long. On joints J, lu and 11 a pair of 

 large dorsal tubercles transversely arranged, each crowned 

 by a little bunch of 8-12 robust prickles. Ou joint 5a pair of 

 similar tubercles, but still larger, ol a yellowisji color, and 

 mamma-like. On joints 4, (i, 7 and 9 tubercles similar to 

 thof " ■ ■ 



joiutsS, 10 and 11 btit smaller. On joint 12 four ^^^ 



black \)rickly dorsal horns, quadrangularly arranged ami 

 eacli about 0.03 Inch long. Spiracles and legs blackish. 



t As loug ajjo as IS.'iU, the late Dr. Harris, as wi' learn 

 from a letter of his to Miss Morris, recently pnljbslied in the 

 Harris Correspondence (p. 245), was aware of the exisii nee of 

 these curious cases. He speaks of them as "the little haly 

 cones of the bases of leaves upon willows and poplars, inio 

 which these caterjjillars [Limenilis disippus and Lim. ursula\ 

 retire for protection during the winter, and in which tliey 

 remain unchanged until the following spring. " It appears 

 also, Irom a brief notice in the Proceedings of tlie Boston 

 Socicli/ of Natural History, Nov. 27, l»(i7, that these larva 

 cases w eknown both to Mr. Trouvelot and to Mr. .San- 

 born at Iciust as early as the year 18G7. 



