June 1S91.] 



PSYCHE. 



95 



PREPARATORY STAGES OF HETEROCAMPA UNICOLOR PACK. 



BY HARRISON G. DYAR, NEW YORK. 



The eggs were not observed but I believe 

 that I have found the larva in its first stage 

 which is as follows : — 



First stage. — Head cordate, black, shiny, 

 a large white patch in front covering the 

 clypeus and labrum ; width .4 mm. Body 

 enlarged dorsally at joint 2 and bearing on 

 each side of the cervical shield a smooth 

 elongated process (.4 mm.) of uniform thick- 

 ness tipped by a fine short hair. The anal 

 feet are prolonged into a pair of smooth 

 processes or imperfect stemapoda, a little 

 enlarged at the end and minutely hairy 

 below. Body cylindrical, smooth, shiny, 

 pale green with four fine red-brown lateral 

 lines on each side, the uppermost faint; 

 three patches of red-brown, the first on joint 

 2 dorsally, the second on joint 7 dorsally and 

 laterally and the third on joint 11 and joint 

 12 anteriorly dorsally running forward upon 

 joint io above the feet. Cervical shield and 

 "horns" and anal plate black. Stemapods 

 1 mm. long, green, twice ringed with black 

 the swollen ends red-brown. The legs on 

 joints 7 and 10 are black outwardly. Venter 

 pale whitish throughout. During this stage 

 the larva eats only the lower half of the leaf. 

 Second stage. — Head slightly bilobed, flat 

 in front, pale whitish, more distinctly white 

 in a large patch covering the clypeus. A 

 broad diffuse red-brown band runs to the 

 vertex of each lobe. Ocelli black; width of 

 head .7 mm. Cervical horns short, black, 

 arising from swollen bases and each tipped 

 by a short hair; stemapods 1.2 mm. long, 

 pale yellowish, with a few black dots near the 

 center, the terminal extensile portion crim- 

 son preceded by a black ring. Body pale 

 greenish, not shiny; joints 2, 7, 11 and 13 

 red-brown above as are the feet on joints 7 

 and 10. A broad irregular brown dorsal 

 shade and four fine red-brown lateral lines 



somewhat indistinct on joints 8 — 10. As the 

 stage advances all the red-brown fades out 

 except on the cervical shield; the dorsal 

 shade becomes a band, contracted at the seg- 

 mental sutures and enlarged on joints 7 and 

 11. During this stage and subsequently the 

 larva eats the whole leaf. 



Third stage. — Head slightly bilobed, flat 

 in front, rounded and narrowing a little to 

 the vertex; pale whitish green, a broad dif- 

 fuse brown band on each lobe from the ocelli 

 to vertex; ocelli black; width 1.35 mm. 

 Cervical horns are two short black tubercles 

 on the cervical shield ; stemapods 2 mm. 

 long, faintly reddish with a few elevated 

 black dots, especially below and outside, the 

 tips a little swollen and crimson. Body 

 whitish with three fine faint white lines on 

 each side of the reddish brown dorsal band 

 which is very distinct, covering the cervical 

 shield and anal plate, retracted at each suture 

 and widening on joints 7 and 11 more than 

 on the other segments. Feet and venter 

 concolorous with the body. As the stage 

 advances the body becomes green, the bands 

 on the head and the dorsal band of the body 

 become edged with white and the two 

 remaining narrow undulated subdorsal lines, 

 pale yellow. 



Fourth stage. — Head not distinctly bilobed, 

 about as high as wide, flat in front and nar- 

 rowing toward the vertex; width 2.1 mm; 

 marked a6 before, the inner white border of 

 the brow r n bands very broad, covering nearly 

 all of the front of the head except the clypeus 

 and central suture; antennae and mouth 

 parts whitish; maxillae black inwardly. 

 Cervical horns reduced to mere points; 

 stemapods 2.5 mm. long, whitish, shaded 

 with red-brown at the bases and ends, the 

 few minutely piliferous elevated dots brown, 

 and the extensile part white. Body marked 



