The Stourbridge Observer, Cradley Heath, Halesowen & District Chronicle.
Stourbridge, West Midlands, England, 1875-02-27 00:00:00

THE COLORADO POTATOE BEETLE.

Mr. A. Macdonald writes to The Times from Long.
acre :—Mr. Towend, entomologist to the Agricultural
Bureau at Washington, says, in his report for 1871,
that the Doryph,ora decemlineata, ox Western ten-lined
potato bug, was described by Say, in the Journal of
Natural Sciences, in 1823, as occurring in Missouri and
Arkansas, was so named from the ten black lines on
its wing corners, five on each side. One of the first
notices of its appearance as a destructive insect was in
1861, when Judge Egerton described it as being very
destructive to the potatoe in Iowa; and in 1862 it was
reported by Thomas Murphy, of Atchison, Kansas,
as doing much damage to the crops and being very
numerous. The insect is said to have first fed on a
species of wild potatoe, growing in the far West, and
is stated to have travelled east about 360 miles in six
years, or at the rate of about 60 miles a year. They
are said to be found as far north as Canada, and as far
east as Ohio. The insect is also reported as hailing
made its appearance in the western parts of New York
and Pennsylvania. In 1864, Mr. Walsh reckoned
that if not checked, they would reach the Atlantic
States about 1880. According to his authority, the
eggs, to the number of 700 to 1,200 are deposited on
the young leaves of the potato, attached by one end to
the under side of them, and usually in clusters of from
one to two dozen. The larvw hatch out in a few days
and feed from 17 to 20 days. They then bury them-
selves in the earth, where they change to pupse from
10 to 12 days, then emerging from the earth as perfect
beetles, to deposit more eggs for a second generation.
The Canadian Entomologist states that all their trans-
formations are effected in 50 days, so that the result of
a single pair, if allowed to increase without molesta-
tion, would, in one season, amount to over 60,000,000.
There are said to be three broods annually in Missouri
and Illinois, the last brood remaining under ground
all the Winter, and appearing as perfect beetles the
following Spring. It is stated after a careful exami-
nation of facts, that 1,250,000 dollars worth of potatoes
were destroyed in 1866 in one small portion of the
United States. From this description of the Colorado
potato beetle, and which may be relied upon as perfectly
correct, how unlikely, if not impossible, it is that they
can he ei with the tubers, as they attack only
the leat or the potato plant. Certainly, if the tubers
are packed in any earthy matter, or haying interspersed
any leaves holding living beetles, they might thus find
their way to England; for Professor Daniels, of Wis-
consin University, states that the insect does not die
immediately after laying its eggs, and that he kept a
female alive for six weeks without food after she had
laid 1,200 eggs. There are several pestilential insects
which destroy the Colorado potato beetle, but their
number is too great for enumeration here. Among
the principal ones are the Arma Harpactor-Lebia and
Coecinella and a two-winged fly, Tachina, besides
several other small insects which prey upon it
while it is in a larvax state. The beetle is specially
fond of certain varieties of potato, such as the
Mercer, Shaker, Pink-eye, but avoids the Bench-
blo w, Early Rose, Peerless, and Chili, when
other varieties are to be obtained. The larva is at first
dark reddish brown, but becomes paler and brightens
as it matures. The head is black, and it has a ring of
black on the first segment of the body, and two
rows of black spots on each side. The perfect insect
is about half an inch in length, of a thick oval shape
and of a yellowish creaui colour, with ten black lines
running lengthwise down the wing covers. The head
and thorax are of an orange-brown colour, spotted and
marked with black. As a remedy, Paris green has
been successfully used, mixed with eight to twelve
parts of wheaten flour, or with three parts of wood
ashes, and dusted over the plants; but when used too
profusely it injures not only the plants, but also the
soil on which it falls. Professor McAfee of the
University of Wisconsin, therefore disapproves the use
of Paris green, and recommends hand-picking and de-
stroying the beetles. Still Paris green is recommended
mixed with ten parts by weight of flour to one of
Paris green, to be dusted over the plants when the
dew is on the foliage, using a common flour dredge.
Three pounds of Paris green and thirty pounds of
flour is a sufficient dose for an acre. The result of its
application in 1872, ix Illinois, Wisconsin, Minnesota,
and lowa, was reported by the Agricultural Bureau
to have greatly diminished the ravages of this pest."
Messrs. James Carter, Dunnett, and Beale, the seed
farmers, of 297 and 238, High Holborn, write on this
subject :—" Without expressing an opinion as to the
desirability or otherwise of prohibiting the impOrta-
tion of potatoes from America, we wish, as large im-
p3rters of American potatoes for seed purposes,
.to
state that our experience is that the tubers arrive sin-
gularly free from soil adhering to them. They appear
to be grown on light friable or sandy soil, therefore
the danger of the larvtx of the beetle being deposited in
the suil attached to the potato does not, so far as our
goes,

It will be agreed by men of all shades of political
opinion (says the Gardener's Magazine), that there
should always be strong grounds for any interference
with tho ordiuAry courti,o. of trade, jlz thoc hobro

us there should be some evidence of danger to justify
a prohibition or any serious modification of the import
of potatoes from Ameriea. It must be observed that
the dreaded beetle has a wide geographical range on
the western continent, and would without doubt
soon become acclimatised here if introduced. The
perfect insect is not likely to be brought over as an
accident of a commercial consignment, but the larva
or grub, which is a mere mite of a thing, might be
brought in; not on stalks and leaves perhaps, but in
fragments of earth attached to the tubers and in the
crevices and hollows which potatoes of all kinds possess
more or less. The beetle, we think, is much more
likely to find its way here, as the mischievous anacharis
did, as a precious gift to a fantastic naturalist; but
there is just a shadow of danger of its entering by way
of fragments of earth adherent to potatoes or in earth
used fcr packing. For the present there is a preven-
tive course of procedure possible without any interfer-
ence with the course of trade, and that is a careful
examination of American potatoes on their arrival at
British ports. They should be turned out of the barrels
and repacked, and all packing material (usually there is
none) and debris should be burnt. This may appear a
costly mode of purifying imported potatoes; but it
' must be remembered that such as we obtain from
I America are not destined for Spitalfields or the
Borough, but for seedsmen, who will sell them at from
3s• •to 12s a pound. An imported American potato
i
I is, n the first instance, a fancy article, from which
both producer and vendor derive a large profit, and
such a manipulation as we propose would not seriously
interfere with the trade in the article.