10 
BULLETIN" 539, TJ. S. DEPARTMENT OF AGRICULTURE. 
pale in the upper angle, extending over two-thirds of height of head (0.43 mm.). 
Paraclypeal pieces prominent, sutures converging at the beginning of intersection 
point of head lobes on vertex; setae pale, stiff, pale around base; 
proximal parts of antennae pale whitish, distal amber; lab rum pale 
amber, width 0.32 mm. ; mandibles dark red, black at tips. Cervical 
shield dark brown, width 1.49 mm., length 0.93 mm.; pale line on 
meson extending across the shield, coming to a point before; ex- 
tending over head to intersection of lobes. Body Nile green, pre- 
vailing color on the dorsum greenish white, which almost breaks 
up completely the dark brown transverse bands; longitudinal 
stripes conspicuous, dark brown, somewhat broken. Tubercles 
"ia" and "ib" of joint 3 small, setae short, "iia" and "iib" small, 
seta long; "ia" and "ib" of joint 4, small, seta short, "iia" and 
"iib " small, seta long, caudad of latter is dusky patch, somewhat 
polished; on joints 3 and 4 "iii" is caudo-laterad of "iib, " distant, 
"iv" is cephalad and slightly laterad of "iii," distant, "v" 
cephalo-laterad of "iv," well separated; "iv— v" is coalescent on 
joints 5 to 13, inclusive, arrangement as before; on joint 13 "vi" 
is near "v"; on joints 12 and 13 "ii" is much nearer meson than 
"i," on joint 11 "i" and "ii" arranged in form of square. All 
segments slightly swollen except last two; transverse grooves prominent. Thoracic 
legs dusky; abdominal prolegs pale. 
PUPA. 
The pupa (fig. 4) when freshly formed is pale green, yellowish on abdominal seg- 
ments; later brown and just preceding emergence of adult uniform black; lustrous; 
delicate; length 8.1 mm., width 2 mm. Spiracles ellipsoidal, prominent, except on 
joint 12, obsolete. Dorsum of terminal segment has slight elevation or hump which 
slopes abruptly posteriorly and forms the obtuse tip. Anterior portion of this eleva- 
tion corneous, rugose, and black. At tip is a row of six hooked spines arranged trans- 
versely, about 0.17 mm. in length. Tip of the male pupa is rounded, that of the 
female pupa irregular. Other sexual differences in pupal stage shown in figure 5, a 
and b. Abdominal segments 1 to 7, inclusive, densely and finely pitted on dorsum, 
very abundant and scattered almost over whole surface of first four segments, scant 
and restricted to anterior border of last three. 
Fig. 4.— The lesser 
corn stalk-borer: 
Pupa. Greatly en- 
larged. (Original.) 
COCOON. 
The cocoon is cylindrical, compact, 15.9 mm. in length, and 5.9 mm. in diameter, 
oval in outline, frequently supplied with exit tube at an angle of about 145°; 23.9 to 
30 mm. in length and 4 mm. in diameter; lined 
throughout on inside very smoothly with silk 
and covered without with sand and dirt particles. 
(PI. II, figs. 3 and 4.) 
ADULT.i 
Expanse 17-22 mm. Head brown to blackish. 
Labial palpi erect, not recurved; somewhat 
longer in the male than in the female and more 
slender, heavily scaled, lying close together on 
the shining crest which is hollowed out for 
them; somewhat clavate toward the tip, end 
member very short, about one-eighth the middle; 
groove for the pale papillary tufts reaching 
almost to the apex and very deeply impressed, 
within bearing a longitudinal white stripe which broadens somewhat at the end of 
Fig. 5.— The lesser corn stalk-borer. 
Comparison of terminal segments of 
male and female pupae showing sexual 
differences: a, Female; b, male. Greatly 
enlarged. (Original.) 
Basal segments pale gray outside, 
i Compiled from descriptions of Zeller and Hulst by the junior author. 
