The Elk County advocate. [volume] (Ridgway, Pa.) 1868-1883, 1874-05-14
THURSDAY, MAY Ia, 1914.
THE COLORADO PorATo Bue.-T

Colorado potato bug, or doryphord de-
cemiineatd, has for several years
past made alarming ravages in the potato
crops of the western section Of the
country. Some forty years ago, it was
known in the Rocky Mountains, where
it seemed to be indigenous, feeding upon
the solanum rostratun,, or wild potato.
When the common tuher was introduced
in that region, the beetle soon attacked
it; aud spreading from one field to an
other, in 1859 it had reached point
one hundred miles west of Omaha. La
1861 it invaded Iowa, and, crossing the
Mississippi in 1864-5, it has since pro-
ceeded eastward at the rate Of about
sixty miles per year; so that it will pro-
badly reach the Atlantic, unless some
be found for its determination, during
1879.
Professor Hall, of Chicago, states
that tie beetle lays its eggs on the
under side of the potato leaf. These
are. speedily hatched. The larva, when
full grown, is over half an inch long,
very thick 10 the middle, and taperiDg
towards head and tail. 1t rs of palo
yellow color, often dusky or freckled on
the back, with small blackish dots, and
along each side are two rows of large
black dots. The legs are black, and
the head black and shining.
The mature insect; the beetle itself,
is nearly half an inch long and quarter
of an inch wide. Its shape is oval, very
convex above and fiat beneath; of a
hard orustaceous texture, smooth and
shining, and of bright straw color, the
head aud thorax being sometimes tawny
yellow; head aud thorax marked with
black spots: the wing cases with black
stripes arranged longitudinally, five on
each case. The anteun9 are twelve
jointed; the first FIVE joints are pale or
tawny yellow, the remaining joints black
the last joint being small, and sunk into
She penultimate one. The legs are
tawny yellow, the hips, knees, and feet
being usually black. 1t requires less
than a month to pass from the egg to
the beetle state.
Where the bug once gets footing,
it speedily destroys the entire crop, 1t
is believed to effect all its transtorma-
tions in fifty days, so that single pair
would, if unmoIested, produce sixty
millions of progency in single season.
Various modes of preventing its ravages
have been suggested, Brushing or
shakiug the lave from the haulm into
vessel is sometimes tried, but this is a
laborious and dangerous operation.
Dusting the leaves with white hellebore
powder is an effective remedy when it is
we'll done; the powder must however, De
freshly ground, as it loses its efficacy
when kept to long. Paris green is also
recommended, but both powders are ir-
rtatine to those applying them, while
tn latter is extremely poisonous. Birds,
it is said, will not destroy the bugs, as
the emanations from their crushed bodies
are noxious even to human beings, and,
it is said, have caused several deaths;
The symptoms resemble those caused by
the bite of the ratlesnake. The beetle
has several insect enemies, especially
some varieties of ladybird, which prey
upon its eggs and lav@.
There has been considerable alarm in
England, lately, lest the pest should be
imported thither in American potatoes,
and official investigations have been
made in order to determine the advisa.
bility OF prohibiting importat!ons Of the
vegetables. The report, however
points out that the lav@ Of the parasite
are not deposited in the tubers or con-
veyed by them, and that with the exer,
else of proper care no danger need be
apprehended froni bringing American
potatoes into the country.