The Republican. [volume] (Oakland, Md.) 1877-current, 1926-08-05
MEXICAN BEAN BEETLE IN
VADING GARRETT COUNTY
Crops In Southeastern Section
Are Being Damaged by Pest

During the past week the Mexican
bean beetle has made its appearance
in Garrett county and has done con-
siderable damage in the territory ly-
ing adjacent to the POTOMAC River.
Investigations show that practically
every garden and bean crop in Kitz-
miller, Kempton, German and other
communities along the river are in
Tested, and isolated gardens in the
vicinity of Oakland have also been at
tackled. The beetle made its appear
ance in the Ryan's Glade section and
is apparently moving in northwest
erly direction. Those whose gardens
have not been infested should be pre-
pared as the insect is apt to appear at
any time and spreads rapidly.
The Mexican bean beetle is a new
insect in this part of the country COM
ing here from the South where it has
already done much damage. The bee
tie is nearly hemispherical, one-fourth
Of an inch long and about one-fifth of
an inch wide. Each of the brown wing
covers bear eight black spots. The
beetle closely resembles some of the
native beneficial ladybirds to which
family the insect belongs. The larva
is orange colored, varies in length
from about one-twentieth of an inch
when young, to about one-third of an
inch when full grown, and is covered
with long, branched spines. Injury
by the larva and adult of the Mexican
bean beetle to the bean plant is char
acteristic. The adult, feeding from
below, eats ragged areas in the lower
surface of the leaf, but often cuts
through the upper surface, giving the
foliage lace-like appearance. The
larvea usually feed on the under sur
face of the leaf, leaving the upper
surface intact. The lower tissue is
cut away in narrow parallel sections
about the length of the insects body.
Between these sections are narrow
strips which are left untouched by the
larva, resulting in a peculiar network
not likely to be mistaken for the work
of any other insect. All parts of the
plant above the ground are fed upon
by both beetle and larva. When the
insects are numerous, the plant is de-
stroyed and presents the appearance
OF having been completely dried out.
After destroying the foliage, the in
sect may attack the pods and even the
stems. Injury to cowpeas and soy
beans is similar, but attack on the
stems and pods of these plants is very
rare. When the beetles are abundant
bean crop may be destroyed in four
weeks or before the pods are grown.
The Mexican bean beetle can be
successfully controlled by the use of
certain arsenical poisons. Although
spraying with liquid poisons has Civ
en- consistently better results against
this beetle than busting, the latter
form of poison is becoming more pop
ular year by year, and in the infested
territory most growers prefer to ap-
ply insecticides to their beans in dust
form. Also where medium infestation
exists, busting gives good results. The
following mixture has been success
fully applied:
Calcium arsenate, l part; hydrated
lime, parts. T
The dust should be directed to the
undersurface of the leaves, covering
as much surface as possible. Enough
of the mixture should be applied so
that between two and three pounds of
the arsenical in the dust is distributed
on an acre of beans. Dust mixtures
may be prepared on the farm by plac-
ing the ingredients in steel drum or
barrel, which is then tightly .'losed
and rolled about for distance of 400
or 500 feet. At the same time it should
be tipped on end at intervals of about
so feet.
There is practically no danger of
arsenical poisoning from consumption
of treated beans, but they should be
rinsed twice in clear water before
marketing to assure absolute safety.
The following stores are purchasing
calcium arsenate to sell for the con-
trolling of this insect: Gonder's Phar-
macy, Oakland; Oates Store, Gonna
mia, w. Va; Hamill Coal Co., Kitz-
miller; Davis Coal Co., Kemptcn, Md.
State Entomologist E. N. Cory and
his assistants will be in the county
the latter part of the week, and in CO.
operation with your County Agent
will make an extensive study for the
purpose of determining the best
means of controlling this insect.