THE SUGAR-CANE MOTH BORER. 
15 
Epipharyngeal shield (PL IV, fig. 6) (ES) not sharply defined, merging in a 
broadly chitinized area on the central forward part of the labrum. Epipharyn- 
geal setw (ET) triangularly grouped, well behind anterior margin of epipharynx, 
moderately long, narrow, equidistant. Epipharyngeal rods (ER) indicated only 
by their prominent posterior projections. 
Maxillulw normal. 
SPECIFIC DESCEIPTION. 
Summer form (PI. Ill, figs. 1, 3; PL IV, fig. 2) : Head slightly trapezoidal in 
outline viewed from above ; widest at the level of the posterior seta P 2 ; lateral 
and frontal margins nearly straight; posterior region broad, not constricted; 
ultraposterior setse of epicranium forming a very obtuse angle, with the apex of 
the angle pointed to -the longitudinal ridge (LR) ; color rich brown, varying to 
black at mouth parts and to orange on dorsal aspect. Prothoracic plate pale 
brown, tinged with black ventrally. Body 
white. Tubercles light brown or paler. 
Abdominal tubercles II oval and about 
twice as far apart as tubercles I. Seta} 
yellow to brown. Imaginary lines con- 
necting setse I and II of abdominal seg- 
ments 3, 4, and 5 (text fig. 3, a) on each 
side, if prolonged, form angles averaging 
30.2 degrees. Tubercle I on ninth ab- 
Spiracles 
(10 speci- 
^■^^ /CO 
dominal segment discernible, 
dark brown. Average length 
mens) 25.6 mm. 
Winter form (PL III, fig. 5) : Differs 
from the summer form in the following 
characters : Color yellow to rich brown, 
varying to black at mouth parts and to 
yellow on dorsal aspect. Prothoracic 
plate yellow. Body tubercles white or 
pale yellow and not easily distinguished 
from ground color of body. Spiracles 
dark brown, distinct and sharply con- 
trasting with rest of body. Average 
length (10 specimens) 22.4 mm. 
As the nearly related species Diatraea zeacolella is liable to con- 
fusion with D. saccharalis crambidoides, Mr. Heinrich has furnished 
the following descriptions : 
Fig. 3. — a, Fourth abdominal segment, 
dorsal view, of larva of sugar-cane 
moth borer (Diatraea saccJiaralis crant- 
hidoidcs), and diagram of angle formed 
by imaginary line through bases of 
setae ; b, same for larger corn stalk- 
borer (Diatraea zeacolella). 
SPECIFIC DESCEIPTION OF LARVA OF DIATEAEA ZEACOLELLA. 
Summer form (PL III, figs. 2, 4) : Head broadly oval, widest at the level of 
posterior puncture P b ; the lateral and frontal margins slightly but evenly 
rounded; posterior region slightly constricted, narrower than middle of head; 
ultraposterior seta? forming a very obtuse angle, with the apex of the angle 
pointed to the lateral margin. (PL IV, fig. 3.) Color yellow, varying to black 
at mouth parts. Prothoracic plate yellow. Body white. Tubercles dark 
brown, contrasting sharply with ground color of body. Abdominal tubercles II 
narrowed and about four times as far apart as tubercles I. Setae yellow to 
brown. Imaginary lines connecting setse I and II of abdominal segments 3, 4, 
and 5 (text fig. 3, &) on each side, if prolonged, form angles averaging 53.3 
degrees. Tubercle I of ninth segment not discernible. Spiracles black. Aver- 
age length (3 specimens) 25.2 mm. 
