64 



BULLETIN 918, U. S. DEPARTMENT OF AGRICULTURE. 



genital plate heart shaped; bursa copulatrix with two opposite, strongly chitinized, 

 hornlike, serrated invaginations (fig. 9, C). 



Alar expanse 15 to 20 mm. 



Full-grown larva. — The full-grown larva (fig. 10, A) is 11 to 13 mm. long, 

 cylindrical, white, with dorsal side strongly suffused with pink. Head reddish brown 

 with blackish brown mandibles and the other trophi yellowish. Thoracic shield 

 rather small, divided in the middle, dark brown. [On each side of the thoracic shield 

 is a small, slightly depressed, kidney-shaped spot, thinly chitinized and less pig- 

 mented than the rest of the shield. This purely specific character is easy to observe 

 and may be of some assistance as contributory evidence in a preliminary determina- 

 tion of the pink bollworm in the field (fig. 11).] Anal plate small, dark brown. 



-A 



TE,M 



AH 



AX 



B 



Fig. 10.— Pink bollworm: A, larva. B, schematic chart of arrangement of body setse of larva. TI, 

 first thoracic segment; T II, III, second and third thoracic segments; A III, third abdominal seg- 

 ment; A VIII, eighth abdominal segment; A IX, ninth abdominal segment; A X, tenth abdominal 

 segment. (Busck.) 



Tubercles small, but distinct, yellowish brown, surrounded by deeper pink than the 

 prevalent suffusion and bearing rather short, dark-brown seta;. Crotches of abdom- 

 inal feet 15 to 17. 



Pupa.— The pupa (fig. 6, A-D) is 8 to 10 



mm. long, rather plump, reddish brown; •"' • 



posterior end pointed and terminating in a f 



short, stout, upwardly turned hooklike cre- 

 master; entire surface finely pubescent; no 

 long setae, spines or hooks, except on last 

 joint; fronto-clypeal suture distinct and 

 curved sharply upward; clypeus, labrum, 

 pupal eyes and mandibles distinctly indi- 

 cated; antenna? diverging at their extreme 

 tip and not reaching to the tips of the 

 wings; metathoracic legs reaching slightly 

 beyond the wings to fifth abdominal segment. 

 Spiracles small, normal. Anal opening 

 large, slitlike, surrounded by strong hooked 

 setae, 5 or 6 on each side; cremaster sur- 

 rounded with 6 to 8 similar, strong, hooked 

 setae. Genital opening slitlike, single in 

 both sexes. When mature, the pupa be- 

 comes much darker (fig. 6, C); the imago's 

 eyes can be seen prominently under the 

 gena of the pupal skin, and the segmentation of the adult antenna; and legs become! 

 discernible. 



o 



Fig. 11. 



-Thoracic shield of pink bollworm 

 larva. (Original.) 



