Montgomery County sentinel. [volume] (Rockville, Md.) 1855-1974, 1874-06-19
THE SENTINE Ell.
The Potato Bug.


The Report of the Agricultural Department
for 1871, at pages IA and rs contains the fol-
lowing description Of the two bugs which prey
upon the nolato leaves, and which are now
committing their rayages 10 different localities:
The Dorgphora decem-lineata, Colorado, or
western ten-lined potato bug, was described
by Say in the Journal of the Academy of Nat
ural Sciences, in 1923, as occurring in Mis-
souri, and Arkansas and was SO named from
the ten black lines on it's wing-covers, FIVE on
each side. One of the first notices of its ap-
pearance, as destructive insect, was in 1861,
when Judge Edgerton described it as being
very destructive to the potatoes in Iowa; and,
in 1862, it was reported by Thomas Murphy,
OF Atchison, in Kansas, as doing much dam
age to the crops and being very numerous
The insect is said to have first fed on species
of wild potato, growing out in the far West,
and is stated to have Travelled east about three
hundred and sixty miles in six years or at
rate OF about sixty miles q year. They are
now said to be found as far north as Canada,
as far east as Ohio, and, according to some
papers, but doubtful, even in New York and
Pennsylvania. In 1864 Mr.. Walsh calculated
that, If not checked, they would reach the At
lantic States about the year 1880. The eggs,
to the number of seven hundred 10 twelve hun
dred, are deposited on the young leaves of the
potato. These eggs are attached by one end
10 the under side of the leaves. usually in clus-
tiers Of one TO two dozen. The larvae hatch
out in few days, and feed from seventeen TO
twenty days. They then bury themselves in
the earth, where they change into pupe, and
remain rs pup9 from ten to twelve days, and
finally emerge from the earth as perfect beetles
to deposit more eggs for second generation.
In order to give some idea of their powers Of
multiplication and the injury effected by them,
the Canadian Entomologist states that all their
transformations are effected in fifty days, so
that the result ola single pair, If allowed to
increase without molestation. would, in one
season, amount TO over sixty millions. And
Mr.. Walsh, after a careful examination of
facts, states that in one year (S66) these in
sects had destroyed one and quarter million
dollars worth of potatoes in one small portion
of the United States which came under his Oh
servation. The insect, after laying its eggs,
does not die Immediately, Professor Daniels,
of Wisconsin University, having kept a female
alive six weeks without food after she had laid
twelve hundred eggs There are said to be
three br0ods annually in Missouri and Illinois,
the last brood remaining underground all
winter and appearing as perfect beetles the
following spring. This insect is stated, to
possess poisonous properties when incautiously
handled; but the Canadian Entomologst has
been unable to find any evidence of poisonous
properties, and doubts the statement. 1t feeds
upon the potato, tomato, egg-plants, thorn
apple, black henbane, &c.
The are several parasitical insects which
destroy the Colorado potato-hug but their
numbers will not admit of their being emu
merated in this article. Among the princi-
pal ones are several plaut-b bugs, Armp, lar
Yactor, &c. some beetles Le6ia, Coccnella,
&c; a two-winged fly, Tdchiaa, beside sever
al other insects which prey upon il in the
Iaryal state, and serve essentially tc lessen The
number of these pests. These insects should
by all means be protected in the potato-helds,
and suffered to increase. The arva of the
Colorado potato-bug is at first dark reddish
brown, but become paer, and brightens as il
natures. The head is black, and ii has ring
OF black on the first segment Of its body, and
two rows of black spots on each side. The
perfect insect is about hnlf an inch in length,
of a thick, oval shape and of yelluwish
cream-color, with ten black lines running
lengthwise down the wing-covers. The head
and thorax are of an orange-brown color,
spotted and marked with black. There is an
other insect closely resembling the Colorado
bug in form, colorntion and markings. This
is called the Doryphora .jUacta, and may be
distinguished by having the second and third
strips always united behind, and sometimes
before, giving ii the appearance of having only
eight strips instead of ten on the wng-covers.
This insect has not yet been reported MS having
done any material injury to the potato, al
though in A abama it has been said to injnre
the potato slightly, and is found in Maryland,
Virginia and South Darolna, feeding on the
.Soiaaum coroliaeace, and sometimes Injuries
eeg-plants in the South. A second insect,
three lined potato-b beetle, lena irilineatd,
has also recently been mistaken for the Colo
RADIO bug but may readily be recognized by
its similar size, more eongate form, and hav-
ing only three longitudinal black lines on It's
reddish-yellow wing-covers. The larva may
also readily be distinguished by its habit Of
carrying Il disgusting lss OF excrement on its
bnck. and by its smaller size. Some OF the
canlhhrides, Epicaata pi1ata, and lemniscata,
are also sometimes confounded with the Colo
RADIO beetle by farmers; and, although they
are striped in a similar manner on their wing
covers, they may be known by their much
narrower aud elongate form and narrow tho
rax The Colorado bugs are partial 10 GER
tain varieties OF potatoes, such AS Mercer,
Shaker. Pinkeye. &c. avoiding as much as
possible the Peachblow, EARLY Rose, Peerless,
Chilli &C., when other varieties are to be OBJ
tanned.