16 



BULLETIN 740, U. S. DEPARTMENT OF AGRICULTURE. 



Winter form (PI. Ill, fig. G) : Differs from summer form in the following 

 characters : Body tubercles white or pale yellow and not easily distinguished 

 from ground color of body. Spiracles black, very distinct, and sharply con- 

 trasting with rest of body. Average length (4 specimens) 24.5 mm. 



THE PUPA. 



On molting for the last time the larva enters the pupa stage, the 

 quiescent period of the insect. The pupa (fig. 4) at first is white, 



but soon changes to a dark 



cl. 



at- 

 9 



brown. It is cylindrical in 

 form and bears little resem- 

 blance to either the larva or 

 the moth. The following 

 technical description has 

 been written by Mr. Carl 

 Heinrich : 



GENERAL CHARACTERS. 



Elongate ; slender, pilifers 

 well developed ; maxillary palpi 

 present ; prothoracic and meso- 

 thoracic legs not extending ceph- 

 alad between sculptured eyepiece 

 and antenna ; sculptured and 

 glazed eyes, labrum, frontocly- 

 peal suture, and invaginations 

 for anterior arms of tentorium 

 clearly indicated ; front ex- 

 tended upward into two hornlike 

 projections; maxillae prominent, 

 only half the length of the 

 wings; wings extending to mid- 

 venter of fourth abdominal seg- 

 ment ; mesothoracic legs not ex- 

 tending to end of wings; meta- 

 thoracic legs extending to, or a 

 trifle beyond, tips of wings; 

 femora of prothoracic legs 

 clearly indicated; antenna? not 

 reaching tips of wings; body 

 roughened but without hooks 

 or prominent set;c ; cremaster absent ; posterior end broad ; tubercles of the 

 eighth, ninth, and tenth segments developed into stout, sharp, thornlike projec- 

 tions ; dorsum of prothorax, mesothorax and metathorax and the first nine 

 abdominal segments rugosely scobinate ; on segments 5, 6, 7, and 8 of the abdo- 

 men the scobinations form a median band encircling each segment; a deep 

 furrow on dorsum separating ninth and tenth abdominal segments ; genital open- 

 ing single and slitlike in both sexes; anal opening a slit terminating in two 

 short lines (JJ ; spiracles elongate, oval, moderate, easily distinguishable. 



SPECIFIC DESCRIPTION. 



Sixteen to 20 mm. long; yellow or yellowish brown, darkest at caudal and 

 cephalic ends ; the front, clypeus, scobinate areas, and enlarged abdominal tuber- 



Fig. 4. — Pupa of sugar-cane moth borer: a, Dorsal 

 view of anterior portions ; b, lateral view of anal 

 segments ; c, ventral view of entire pupa. 



