410 
Journal of Agricultural Research 
Vol. XXIV, No. s 
head; and below this a line running from the ocellar area to the caudal margin of 
the head. This pattern remains constant throughout the remaining instars. Cervical 
plate dusky yellow with small dark spots. Body color pale greenish yellow tinged 
with a faint claret or maroon overcolor. There are four longitudinal rows of whitish 
spots, one on each side of the narrow middorsal line and a broader .one on each latero- 
dorsal aspect above the spiracles, giving the larva a striped or spotted appearance. 
Venter pale green, skin finely granular and glistening. Pinacula dark yellowish 
brown, rugose. 
Instar VI.—Head dusky yellow with conspicuous groups of round fuscous spots; 
frons concolorous with head. Cervical plate yellowish brown, with several dark 
spots. Rest of thorax and abdomen entirely covered with the brown overcolor 
^xcept for the four longitudinal pale or greenish lines which are more conspicuous 
in this instar. Pinacula darker than body, nearly concolorous with dark markings 
on head. Black cicatrices on the pedal segments of the abdomen about the size 
and shape of the spiracles. Caudal plate dusky yellow with dark markings. 
Instar VII.—Head as in Instar VI with the markings more sharply defined. 
Cervical plate dusky yellow with a faint, dark-bordered pale median line, otherwise 
as in Instar VIII. 
Instar VIII.—Head dusky or amber yellow, with dark markings composed of 
close groups of round yellowish brown spots arranged as described under Instar V. 
Frons dusky yellow, outlined with a very fine dark line and outside a pale V, which 
at apex continues caudad to the vertical suture. Cervical plate dusky yellow, with 
narrow, dark-bordered pale median line and some small dark markings. The four 
rows of irregular whitish spots give the larva a distinctly striped appearance. Pina¬ 
cula yellowish brown, leathery, shining, rugose. Cicatrices larger than spiracles, 
black. (PI. 2, B.) 
THE PUPA 
DESCRIPTION 
The pupa is pale yellow when first formed, soon changed to a golden yellow, the 
head, thorax, and wing cases darkening as it approaches maturity. Spiracles are 
present on abdominal segments 3 to 9, inclusive, those on segment 3 almost under 
the edge of the wing cases, those on segments 5 to 8 elevated, the one on segment 
9 pale and merely a scar. Anal process rather narrow (PI. 2, G), a dorsal rounded 
ridge of ne^ly uniform width running to the rather truncate and downwardly bent 
tip. At the angles of this tip stand the setae of the dorsal pair, very small, depressed, 
and inclined cephalad. At each side of the dorsal ridge is a flattened depressed 
area cut by the deep, wide, curved nasal groove at whose caudal end stands a small 
tubercle. Ventrad this anal process is more tapering and ends in a rounded elevation 
from the side of which arises the ventral pair of setse, somewhat larger than the dorsal 
pair and diverging. Cephalad of this terminal elevation are four or five shallow, 
parallel, longitudinal depressions as if made by fingers laid side by side. The tip 
of the abdomen beneath is flattened but not concave. 
THE COCOON 
When fully grown the larva makes its cocoon (PI. i, B) either by walling 
off a section of its burrow or constructing a separate chamber near by in 
the soil, more often the latter. The cocoon is about 15 millimeters long 
and half as wide, shaped like a peanut meat, rather firm to the touch, 
lined with soft gray silk and outwardly covered with earth particles 
so that it is not easily found. It lies close to the surface of the ground 
and when buried deeper has an extension reaching the surface. In 
emerging the moth leaves the pupal shell entirely within the cocoon. 
SYSTEMATIC RELATIONSHIPS 
Crambus mutahilis appears to be the ultimate of one series in this genus. 
It differs from hemiochrellus (i, p. 57), its nearest relative, in the greater 
development of the antennae and the reduction in the male genitalia. 
The male antennae are more strongly pectinate than those of hemiochrel¬ 
lus; in fact, more so than in any other species of the genus which the 
