132 FOURTH ANNUAL REPORT OF 



and the heat, if it can be controlled, should not exceed 80° F. It is a lazy 

 slothful creature, and often rests' for hours in the jDOsition given in Figure 

 56. As we learn from Mr. F. O. Adams, who has lately made an interest- 

 ing report on the culture of this species, * the color of the more mature 

 worms so thoroughly corresponds with that of the leaf on which they natu- 

 rally feed that the^^ can with difficulty be detected while clinging, motion- 

 less, to the branches and leaf-stems. They are of a beautiful clear green 

 with generally' two silvery spots each side on the fifth and sixth joints, and 

 a pale yellow line running along the sides. This line, with the position 

 which the worm sometimes assumes, strengthens the resemblance to the 

 leaf, and I reproduce a rough outline (Fig. 57) from Mr. Adams' Eeport 

 which will well convey this resemblance to the reader's mind — the worm 

 being outlined at a. 



The life of the worm lasts from .50 to 80 days, and it feeds on all kinds 

 of Oak, but prefers those of the white oak group. Dr. Alexander Wal- 

 lace, of Colchester, England, to whom I am indebted for specimens of the 

 moth, and who has extensivel}^ experimented with it, found that the worm 

 would feed also on Beech, Apple, Quince, White thorn, Neapolitan medlar 

 (Photinia glabra) and Chesnut. 



Larval Changes. — The larva in the first stage is yellow with tubercles corresponding exactly in 

 number and position with those of Polyphemus, and the others described at the same age. It has a 

 narrow, but distinct, dorsal, subdorsal and stigmata! black line. The four upper rows of tubercles, 

 (except the two dorsal ones on joint 3, and tTie central one on jt. 11, which are large anddark) are yel- 

 low and give rise to stout black outwardly-curving bristles; the stigraatal row is black with a white 

 basal annulation, and gives rise to white bristles. The bristles are longest on thoracic joints, 

 aud are all white on the first. Head shin j- gum-copal yellow; cervical shield paler, more orange and 

 without polish; a black spot on anal shield and on each anal proleg. Thoracic legs black with yel- 

 low extremities; prolegs with brown extremities. Approaching the fli'St moult, the yellow color 

 becomes more greenish. In the second stage the color of body is greener, the head is chesnut-bvown, 

 the longitudinal lines are almost obliterated, the medio-dorsal oue being of a faint antl delicate blue: 

 there is a broad latei-al band of the same faint blue, witli a light yellowish line below it. The tuber- 

 cles are longer, especially on joints 2, 3 and 4, the dorsal roMS of a delicate yellow, the lower one of a 

 delicate l)lue with yellowish base. The bristles from all are black with a few scattering pale ones . 

 The anal shield is edged with blue. In the third stage there is not much change; the tubercles are 

 relatively still more prominent, the lateral ones tipped only with blue, the green of the body is more 

 intense, and is speckled with straw-color; and the lateral yellow line is suppressed on the thoracic 

 joints. In the foui'th stage the change is slight, but from one to three silvery spots appear on the 

 lateral yellow Jiue, usually on joints 5, 6 aud 7. In the fifth or last stiige, and when full grown, it 

 presents a most beautiful and delicate appearance, but varies considerably, and the following de- 

 scription is taken from those I fed, aud more especially from that which produced themale moth. It 

 is of the same form as Luna and Polyphemus, the joints being deeply Lnsected, narrowing from stig- 

 mata upwards, and flattened on doi'sum by a crescent-shaped depression. Head opaque green with 

 slight bluish tint, the five oceUi distinct and brown; afewpale hairs especially around, anddecurved 

 over, the trophi; antennre with bulbus yellow, the other two joints brown, the last terminating in a 

 long seta; epistoma with sutures and margins pale lilaceous; labrum very large, with pale margins. 

 Cervical shield paler than body, only slightly polished, ridged behind, and edged in front with yel- 

 low. Body clear yellowish-green; tergura of joints (.j— 10 especially) paler, and almost nacreous at 

 insections; studded with minute (().0-2 inch long) short, clavate, sulphur-yellow projections or scales: 

 the tubercles are blue and emit black hairs, and there are besides about half-a-dozen long yellow 

 dorsal, anteriorly-curving sets on joints 4 — 11; joint 1 is small and retractile, 2 and 3 large and ren- 

 dered square by the jirominence of the dorsal tubercles; .'>— 9 subequal ; 9— last diminishing; a lateral 

 pale yellow line, faintly edged above with lilaceous, extends from middle of joint 4 to tip of anal 

 legs; a silvery spot in this band on joint 5, and sometimes on joints 4 and 6. Stigmata immediately 

 below the yellow line, slightly oblique, sub-elliptical, fulvous, with (except on joint 1) a brown 

 fringe; abroad triangular brown patch on anal prolegs, and a broad margin on the caudal plate, 

 extending and diminishing to anterior part of joint 11, also purple-brown. 



*3rd Rep. on Silk-culture in Japan, p. 8. 



