576 
Journal of Agricultural Research 
Vol. XXIX, No. 12 
somewhat elongate and nutant. Labrum ante¬ 
riorly rounded, with a row of short setae, two on 
each side. Clypeus transverse, also with a single 
row of small setae, three on each side. Frons 
distinct from epicranium; several short setae both 
on frons and epicranium. Ocelli absent. Antenna 
(fig. 3, B) short, attached to cranium by a large 
membrane (w), two-jointed; basal joint ring-shaped 
with two setae; apical joint minute, anteriorly 
with two horn-shaped prolongations (h); supple¬ 
mentary appendix (a) conspicuous, ovate. Man¬ 
dible (fig. 3, D) ending with four smooth teeth, the 
two median ones falciform and larger than the two 
others; the proximal of the latter somewhat enlarged 
at base, the distal one slender and pointed; three 
long setae at inner margin near base and one long 
and strong seta on the external side of the mandible. 
Maxilla (fig. 3, C) with large and broad lobe (Z), 
which on the inner margin carries a series of rather 
strong, stiff setae and at the end several smaller 
hairs in a ring around a papilla (p). Maxillary 
palpus conical, three-jointed, with terminal joint 
longer than the two others and medianly on the 
Fig. 1 . —Epitrix parvula: Eggs. 
Greatly enlarged 
outer side carrying a single strong seta. Labium 
proper ( e , fig. 3, C) transverse, posteriorly limited 
by a thinly chitinized arch; one short seta on each 
side. Labial palpus short, two- 
jointed. Ligula lacking. Mentum 
and submentum ( mt ) not separated, 
together forming a large, membra¬ 
nous, rounded region between the 
maxillae, with an anterior and pos¬ 
terior pair of setae. Prothorax with 
slightly chitinized tergal shield, the 
two other thoracic segments entirely 
fleshy. All thoracic segments sparse¬ 
ly provided with setae. 
Legs (fig. 3, A) short and rather 
weak; all equal and five-jointed; the 
fifth joint or “claw’' hook-shaped, 
very curved and pointed; large mem¬ 
branous empodium (e) present. 
First to eighth abdominal seg¬ 
ments (fig. 3, F, H) cylindrical 
and separated by large interseg- 
mental membranes (t). Dorsally each segment is 
divided into three folds, the anterior (1) carrying 
three short setae on e^Mfeside, the second (2) one 
on each side, and the tmrd (3) two on each side. 
Behind the spiracle (s) a single seta (4), placed in 
direct continuation of the two belonging to the 
third fold. Epipleural ( e ) and hypopleural ( h ) 
areas present, separated by distinct ventrolateral 
suture, and each carrying two short setae. 
Ventrally the segment has two transverse short 
folds (v, w) each with a few setae. At the 
base of all the setae are very inconspicuous, 
smooth and shiny, rounded, thinly chitinized 
plates. 
Ninth abdominal segment (fig. 3, G), spatulate, 
posteriorly rounded; two pairs of long setae on its 
dorsal surface, the one pair (1) anteriorly, the 
second pair (2) posteriorly placed; laterally and 
posteriorly with three shorter but well developed 
setae on each side. 
Tenth abdominal segment (fig. 3, E) retractile > 
cylindrical, and long, with the character of a loco 
motory organ. 
Spiracles ring-shaped, small; one mesothoracic 
pair and eight abdominal pairs present 
Larval instars.— First-instar larva 0.7 to 1.4 
mm. long; white except the head, which is yellow¬ 
ish in color. Second-instar larva about 2 mm. 
long; white in color, with digestive tract showing 
darker. Last-instar larva about 3 mm. long; color 
white except on the chitinized parts, as the head 
capsule, which are light brownish. 
THE PUPA 
Uniformly white when first transformed. 
Length about 1.670 mm., width across meso¬ 
thoracic femur about 0.959 mm. General appear¬ 
ance characteristic of the Chrysomelidae. JEIe^d 
bent downwards. Antennae directed caudad, 
about four of middle segments concealed beneath 
the prothoracic and mesothoracic legs, last three 
segments directed toward mesal line and lying 
posterior and nearly parallel to the tarsi of the 
mesothoracic legs. Metathoracic legs only par¬ 
tially concealed beneath elytra and wings, femur- 
tibial elbow approximately even with tip of elytra. 
Elytra overlapping fourth abdominal segment, 
wing almost attaining sixth segment of abdomen. 
Caudal segment of abdomen bearing a pair of 
characteristic hooklike appendages. 
THE ADULT 
The following description of Epitrix 
parvula is by W. S. Blatchley ( 1 ). 
Oblong-oval, subconvex. Dull reddish-yellow 
elytra often with a fuscous transverse cloud at mid¬ 
dle; abdomen brown; antennae and legs pale red¬ 
dish-yellow, the four outer joints of former and hind 
femora of latter often darker. 
Thorax convex, shining, nearly twice as wide as 
long, not narrowed in front; antebasal impression 
evident but not deep; surface distinctly but rather 
finely and sparsely punctate. Elytra very little 
wider than thorax, umbone feeble, punctures rather 
coarse and not crowded on disk: finer and more 
close-set on sides, where the intervals are subconvex. 
Length 1.5 to 2 mm. 
LIFE HISTORY AND HABITS 
LIFE-HISTORY SUMMARY 
The eggs of the beetle are deposited 
in the soil near the base of the tobacco 
plant. They hatch in a few days and 
the larvae begin to feed on the small 
rootlets. The larval stage, which in¬ 
cludes three instars, requires about 29 
days at Quincy, Fla., during the cool 
weather of early spring, but in the hot 
weather of midsummer this period may 
be shortened by more than one-half. 
The pupal stage is passed in a small 
oval-shaped cell just below the surface 
of the soil. Newly emerged adults 
confine their feeding to the lower leaves 
