124 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



more curved than before and directed backward and provided with numerous dense conical tuber- 

 cles; they are pale j-ellowish at base, and rosj' on the distal half, becoming black at the tip, which 

 is still regularly forked: the two pairs are of the same shape and length. The abdominal dorsal 

 spines are much stouter and shorter in proportion than in stage III. The subdorsal (supraspi- 

 racular) spines are simple, conical: the lateral (infraspii-acular) spines are very short, and com- 

 posed of four spines. The "caudal spine" (single median dorsal spine on eighth abdominal 

 segment) /•« nov much stouter, more conical than l/efore; '2. .5 nun. m length and furnished with 

 crowded spines, liut still ending in a regular fork. The suranal plate is as before, but the spines 

 are shorter, and the exterior of the anal legs are ornamented as before. 



The hairs arc now long and ahundanf, some of the dorsal ones longer than the body is thick. 

 The spiracles are very conspicuous, each being surrounded b}- a broad green ring, outside of 

 which is a yellowish ring, which is margined with yellowish })rown. The bodv is dark umber- 

 brown; the reddish spines and the spiracles, as well as the reddish edges of the suranal plate and 

 anal legs, decidedly contrasting with the dark hue of the body. The color of the spiracles varies 

 in different individuals, being sometimes mostly white or green or red. Also the yellow color 

 around it is sometimes large and of different width, sometipies Ijeing reduced to a line. 



The last stage differs from stage IV in the shorter dorsal horns and caudal horn, those on 

 the sides also being decidedly shorter, and the anal legs are larger, with a wider dai'k granulated 

 area on the sides, and the body is much thicker and heaviei', while the head is pale. 



Last (Jifth) sfcu/e. — Length. 1(> cent. (Described from one living on the choke cherry.) 

 Head one-half as wide as the body: width. 7 mm.; deep gamboge-yellow, and green on the side; 

 a double, deep-black frontal line extending from the vertex, diverging below so as to leave a 

 median yellowish line on the upper division of the clypeus. The front division of the cl3'peus 

 (clypeus anterior), the anteiuue. and the base of the jaws yellowish. The thoracic legs and the 

 horns on the second and third thoracic segments and the anal legs with the suranal plate are all 

 of the same color, /. t.. deep shining gamboge-j'ellow. The general color of the body in the 

 green individuals is a delicate pea-green (more usually the individuals are brf)wn or tawney), 

 varying from the shade of the upper side of the cherry leaf to that of the under side, being paler 

 above along the back and especially on the sutui'es than on the sides. The hairs are long and 

 slender and whitish, most of the dorsal ones as long as the body is thick. There is a prothoracic 

 plate of the same green hue as the body. l)ut with yellowish edges. Of the four horns on the 

 second thoracic segment, the outer ones are half as long as the inner or dorsal ones, which are 

 4.5 nun. in length; those of the third thoracic segment are of the same size as those on the 

 second. I'here are four similar l)ut nnich smaller dorsal and subdorsal horns on each of the 

 alidi)Hiinal segments (but they are shorter and more regularly conical than in stage IV). those 

 on each segment being of the same size, the two dorsal ones being almost three times as large as 

 the suixlorsal ones, each dorsal one bearing tiiree terminal spines. Those on the thoracic seg- 

 ments are tul)erculated. ending in a fork. On the eighth alidominal segment is a median dorsal 

 horn, now shorter in proportion than in stage IV. small and short, length 2 mm., nearly twice 

 as large as the other dorsal ones in front, tuberculated and slightly forked at the end. but not 

 so regularly forked as in stage II. There is a minute median one on the ninth segment, and 

 two minute lateral ones on each side of the segment. The spiracles are very large and conspicuous, 

 yellow with an outer ring of very dark green, which is edged on each side with paler green; 

 those on the prothoracic segment are without the deep green outer ring. The suranal plate is 

 resfularlv triano-ular. gambooe-vellow. with a swollen, routrh. coarselv gi'anulated edge, within 



ft. OO'^. ft »ft ft^ 



which the surface is black, with yellow coarse granulations. A similar nari-ow triangular plate 

 on the anal legs. The middle abdominal legs dark pea-green, with a deep ocher-yellow tranverse 

 band above the black plaiita. 



For a careful description of the egg and the larva in its tirst four stages see Dr. J. A. 

 Lintner's Ent. Contr., II, 150. His larvse molted four times, and he thought from the small size 

 of the specimens after the fourth molt that there might be a fifth one. 



The lifth and last stage differs from stage IV in the shorter dorsal horns and caudal horn; 



