MEMOIRS OK rilK NATIONAL ACADEMY OF SCIENCES. 113 



tiouiihly longer seta. There are two .separate niiiuite dor.sal seta: on tlie ninth abdominal .segment, 

 hut tiiev are nuieh nearer togetlier than the homologoii.s ones on the eighth .segment and arise 

 from a common slightly marked low eminence. 



The suranal plate (PI. LIII. tig. L') is eoneolorous with the re.stof the body, not pigmented in tiic 

 middle; the surface is smootii, with no conieal spines, the four setffi on each side not arising from 

 definite tubercles, though there are two terminal, very small, microscopic, setiferous tubercles. 

 At the end of this stage the larva is green, and traces of the seven lines apjjear. 



Stii)/e IT. — Length. 9-1(1 mm. The head is now smaller in proportion than before, Init still 

 black. Prot ho racic shield black. In some of the larvre it is divided in the middle by alight 

 line. The two horns (tig. 4) are now shorter than before in proportion to the body, being 

 about as long as the body is thick, and about two-thirds as long as the body is broad. They are 

 now spinulated, aliout a dozen spinules in sight from one side. The tip is more decidedly forked 

 than in stage I, and the seta? are short— about half as long as the spine is thick. All the primary 

 spines on the other segments are now much larger than before; stout, conical, of nearly uniform size, 

 those of the prothoracic segments being of the same size as those behind the succeeding segment. 

 There are three rows of spines on each side of the body, andtbe dorsal ones arc no larger than 

 tho.se of the subdorsal and subspiracular series. On the eighth abdominal segment there are two 

 widely separate dorsal spines, and two shorter ones on the ninth segment, with the median one 

 now chitinized, black, and as large as that on the eighth segment, but a little more obtuse, with 

 two fine seta?, showing the original double nature of this spine. On the first thoracic segment, 

 which is slightly narrower than the second, are two rounded ])lack flattened conical tubercles, not 

 piliferous, and two smaller Hatter ones behind. Two larger subtriangular subdorsal black 

 tubercles give rise to three minute short hairs. They are represented on the third thoracic 

 segment bv two minute conical, black tul)ercles, the homologous ones on the abdominal segments 

 being minute and greenish, tipped with black. Tho.se on the sides of each segment are larger, 

 acutelv conical and black. On the eighth abdominal segment are four conical black tubercles, 

 two dorsal and two subdorsal, one on each side. On the ninth segment is a single median conical 

 tubercle, not quite so high as those on the eight segment, but larger at the base. The subdorsal 

 tubercles on this segment are slightly larger than those on the eighth segment. Suranal plate 

 with the terminal spine very much larger than in stage I; black, chitinized: and on.each side, near 

 the middle, is a stout, short, conical black spine. On surface and sides are a few well marked 

 but small setiferous tubercles not visible in stage I. The suranal plate is subcordate, being 

 excavated in front; behind it is su))triangular. with two black tubercles at the end, which are 

 smaller than those on the side in front of the middle; the suranal plate is greenish, like the 

 prothoracic .segment, while the body is tinged with yellowish, with eight faint rather broad 

 whitish longitudinal stripes. Along the underside of the body is a band, which varies from light 

 lemon-yellow to reddish, and is usually darker on the underside of abdominal segments 8 and 9. 

 The spiracles are black. The thoracic legs are black. The anal legs are greenish, with a blackish 

 patch on the outside near the planta. 



In this and the next stage it continues to feed on the underside of the leaf. Directly after 

 shedding the skin the head and horns are pale yellowish brown. 



At the end of this stage the body is somew^hat reddish above, as well as beneath, while the 

 longitudinal stripes are reddish. 



Stage III. — Length, 12-14 mm., at end of the stage, 21 nun. The head is now chestnut red 

 to pale sienna brown; width. 2 mm. Iii this stage first appear two square })lack patches on the 

 prothoracic plate, and a trapezoidal patch on the suranal plate. 



The two horns (PI. LII, fig. 4) are now longer and slenderer than before, tajjering rather 

 more, and with more setiferous spiimles. On the top of the protlioriicic segment are two square 

 black spots, in some cases there are four, extending back from each spine; a nai-row one on each 

 side of the two square middle ones, while the two middle ones may be divided, making six in 

 all. or all mav lie wanting. The four prothoracic spines are now mor(> developed, forming low 

 conical warts. The dorsal spines on the last thoracic and first seviMi abdominal segments are 



