2 BULLETIN 892, U. S. DEPARTMENT OF AGRICULTURE. 
The beetle is variable in color and especially in markings, and in 
size, the length being from one-fourth to one-third inch. It is of 
oblong form, narrowing in front, and the color varies from pale yel- 
low or buff to nearly black, while the elytra or wing-covers are uni- 
formly yellowish or darker, but usually more or less distinctly striped 
with black. The beet-feeding form most commonly found is illus- * 
trated in figure 1, a. 
The technical description by Dr. Geo. H. Horn (4)* follows: 
THE GENUS MoNoxtA LEc. 
Head oval, moderately convex, not deeply inserted, front feebly or not im- 
pressed. Antenne filiform, not longer than half the body, third joint as long 
as the first, fourth longer than the second, joints 6-10 subequal in length; 
labrum moderately prominent, truncate with rounded angles; maxillary palpi 
moderately stout, second and third 
joints obconical, the terminal coni- 
cal and more slender; prothorax 
transverse, widest at base, except 
in sordida; scutellum oval at tip; 
elytra oblong, scarcely broader be- 
hind the humeri, closely and irregu- 
larly punctured, the side margin not 
prominent; epipleurz narrow, but 
extending nearly to the tips of the 
elytra; prosternum entirely obliter- 
ated between the cox, the coxal 
cavities open behind. Legs moder- 
ate, the anterior tibie indistinctly 
grooved on the outer side, tibize 
without terminal spurs; tarsi shorter 
than the tibiex, the first joint as long 
as the next two; claws dissimilar in 
the sexes, finely bifid in the male, 
Fic. 1.—Western beet leaf-beetle (Monozia absolutely simple in the female. 
puncticollis) : a, beetle; b, eggs; 9, claws 
of legs of female; @, ditto of male. a, MONOXIA PUNCTICOLLIS Say. 
much enlarged, 0, more enlarged. QO ¢ ; : : : : 
highly magnified. Form oblong, narrowed in front; 
Surface finely pubescent, color vari- 
able from pale yellow to entirely black, or with the elytra vittate. Antenne vari- 
able in color from entirely black to pale, generally with the outer half dark, the 
base pale, fifth joint always shorter than the fourth or sixth. Head coarsely 
and closely punctate. Thorax not quite twice as wide at base as long at mid- 
dle, broader at base than apex, sides freely arcuate, base broadly emarginate 
at middle, oblique each side, hind angles distinct; disc usually irregular, with 
broad, vague depressions each side, so that at times the sides of the thorax 
appear deplanate, a vague median impressed line, surface very coarsely and 
irregularly punctate; elytra closely punctate and finely pubescent, the punctures 
coarser near the base, fine and closer toward the sides and apex. Body be- 
neath finely sparsely punctate and pubescent. Length .27—.34 inches; 7-8.5 mm. 
Male. Claws [fig. 1, .¢] finely bifid at tip; last ventral segment obtuse, with 
a short median linear impression near the apex. 
* Figures (italic) in parenthesis refer to ‘‘ Literature cited,” p. 23. 
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