Evening star., 1942-06-21

Inc Japanese DSeIle Is genera
upon many ACKNOWLEDGEMENTS, shI
waited crops. However, the injury t
upon grass roots is probably the
most serious. Especially is this
true when we consider how hard it
Is to have a good lawn under normal
circumstances. With the beetle
grubs eating the roots, good lawns
become even more difficult.
The beetles normally emerge dur
ing late June and early July. This
year they are already beginning to
feed upon our roses and ornamen-
tails. Thy feed greedily for four to
six weeks before the eggs are laid
in the soil and the adults die. The
eggs soon hatch and the gruos
feed upon plant roots until cold
weather forces them into hlberna-
tion. AS soon as the weather warns
I'D in the spring they return to
their feeding and continue until just
before emergence. Thus they feed
upon the roots of our lawn grasses
and other plants from September
until May.
While the beetles may be present
from mid-June until october in
Washington yards their greatest
density is usually between early July
and late August-nearly two
months. During this period they
will be found feeding upon their
favorite food plants in swarms, al
though many sections have as yet
to feel their full force. This is be-
cause they travel along main routes
auto roads in particular. North
east Washington was the first to-
suffer and today still is receiving
greater injury than most other
sections.
Normally the density of the jap
snese BEETLE invasion increases Tor
about three years or until their ma
tural enemies begin to curb their
numbers. They have three groups OF
enemies: A tiny parasitic wasp that
feeds upon the adults. 1t has been
cultivated by agencies interested IN
curbing this destructive pest. Ger
tain of the nematodes attack the
erubs. And, third, bacteria com
rnonly known as the Milky disease"
This disease is being cultivated and
distributed by workers at the Uni
versity of Maryland.
OF course birds feed upon the
beetles and grubs, especially the
much maligned startling who eats the
adult beetles. No doubt the mole
hunts the grubs of the japanese
beetle as well as those Of the June
bug.
Manv of us have heard, when first
reported. that the japanese beetles
stripped the foliage and flowers from
every kind of plant, but that is not
true. They do attack great many
kinds of plants, but they have their
favorite foods to which they go.
In general the beetles favor the
American elm, white birch. horse
chestnut. linden and willow trees;
the ounce, apple, peach, cherry'
plum. raspberry, blackberry, oiue-
berry and grape among the fruits.
Kerria, button bush, hollyhock, rose,
Gamma, mallow and many other flow
ers and shrubs are included IN their
preferred diets, although they seem
to favor those with ight-coloreo
blossoms. Sweet corn is the only
vegetable mentioned in the list, al
though there are others which are
subject to attack to lesser extent.
The control of the japanese beetle
has been extensively studied by State
and Federal workers. Briefly, tour
lines of approach are listed for the
home gardener. The beetles may
be poisoned, traps may be used,
the beetles may be hand-picked ana
we may destroy the grubs with
poisons.
Poison sprays on the foliage of
plants are not as fully effective as
we should like. Unless especially
prepared for this particular pest
they are not likely to do any good.
Lead arsenate, the common stomach
poison used for the control of chew
ing insects, should be mixed with a
1ow-grade wheat flour q ounces
powdered lead arsenate and IL
ounces of -four to gallon of water).
On those plants injured by the lead
arsenate or on which we prefer not
to use a poison we may spread with
lime and wheat flour. This is a
repellant only. The newest control
for insects-derris-when prepared
specifically for the job is effective
against the beetle and is not toxic
to warm -blooded animals.
Beetle traps are very good and
will catch many hundreds of the
adult beetles. Use yellow trap,
Ior that color seems to attract them
more effectively than a green one.
The bait-geraniol or some COM
pound containing twill draw the
beetles from a considerable distance.
1t is for this reason that traps should
not be used until the beetles are
present in considerable numbers.
Otherwise you may be attracting
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