THE ROUGH-HEADED CORN STALK-BEETLE By 
pupa stage the larva les on its back, in a slightly curved position, 
in the cavity formed by its movement in the soil. While still inclosed 
in the old integument, the larva undergoes its transformation into 
a pupa. This process is initiated by the withdrawal of the internal 
mass of the body from the larval integument at its hind end, which 
becomes greatly shriveled. Finally, when the pupal body has been 
formed, the larval skin | 
splits along the dorsal “% 
line, revealing the fully | 
formed pupa within. 
The latter frequently 
passes its entire exist- 
ence inclosed within the 
split larval skin. 
PUPA 
DESCRIPTION 
The pupa of HLuethe- 
ola rugiceps measures on 
the average a bout 15 le. 5.—Ventral view of posterior end of abdomen of 
mil linneters mie eMetae charactors (Diawaie Hore is) 
and is pale buff. Its 
general form is shown in Plate IV, A, and certain of its structural 
features in Figures 4, 5, and 6, but probably its most distinctive pecul- 
larities are those of the mouth parts (fig. 4). The mandibles are 
relatively stout, roughly triangular in outline, and with the apex 
forming a rounded angle. The labrum is quite wide transversely, and 
has its free edges regularly and evenly arcuate. The maxillary palpi 
are short, conical structures which 
are nearly vertical in position and 
have their tips projecting but 
slightly below the level occupied 
by the other mouth parts. 
Other distinctive characters are 
afforded by the shape of the post- 
coxal process of the prosternum, 
which is rather short, blunt, and 
constricted near the middle, and 
by the elytral pads, which are 
smooth, or, at most, only ob- 
scurely costate. 
Pe en ek of postétion ena of Sexual characters in the pupa 
abdomen of female pupa of Huetheola occur 1n the ventral surface of the 
Cea by Hee Foe CEES ‘Vast abdominal segment. In. the 
male this bears a prominent hemi- 
spheric protuberance, the apex of which is slightly indented (fig. 5) ; 
in the female this structure is lacking, but instead there is a minute 
median projection of the anterior border of this segment into the 
segment in front (fig. 6). This process shows a pair of lateral, more 
ez, ; ot 
- fully chitinized areas which probably correspond to the genital plate 
of the adult female. 
94051°—24—_-3 
