Q. In past years I have had major problems
with Japanese Beetles. They are especially
destructive to string bean plants. Can you
suggest some organic remedy to rid of these
A. You have touched upon a longtime nemesis of our garden plants. I remember first confronting them in Ohio around 1963. They are as ugly as they are nasty and voracious.
Organic compounds have not been very successful against these large critters. You could try the Safer Insecticidal Soap products which have been out for a while and have a greater range of success than prior mixes.
I have not attempted to control them with Safer's
but you could give it a try. I had read of an insect that was being experimented with to see if the beetle larvae would be eaten. Once they have developed that hard outer shell they are hard to penetrate and kill. The larvae may be the better stage of the insect to attack.
Check with your local ag department as to whether there is a beneficial insect available
and if they are using any nontoxic organic compounds in the eradication. If you find out something newsworthy please tell me!
Q. I have some Japanese beetles in my
garden. What should I do?
A. Please treat them as soon as you can. They are terribly destructive and eat rapidly. Follow the label instructions always and take care to avoid breathing in the spray
apply on a still morning and wash hands and arms carefully with warm soapy water after use.
Here is pertinent info listed in this order:
Amount to Mix with 1 Gallon Water
Amount to Mix with 10 Gallons Water
Cythion 57% EC (Malathion)
1 1/2 fluid ounce
Do not use on Boston fern maidenhair fern
gloxinia some red carnations or maple or hickory under stress. Highly toxic to bees
Dymet (20/10) EC (Methoxyclor and Diazinon)
Marlate 50% WP (Methoxychlor)
5 fluid ounces
Marlate 25% WP (Methoxychlor)
9 fluid ounces
Orthene 75 S (Acephate)
2 fluid ounces
Repeat applications of two week intervals as necessary
Sevin 50% WP (Carbaryl)
1 1/2 tablespoons
3 fluid ounces
Mites and aphids sometimes become a problem after Carbaryl sprays. Carbaryl is highly toxic to bees. Do not use on Boston ivy.
Adult Japanese beetles are 3/8-inch long
metallic green beetles with copper-brown
wing covers. Five small white tufts project
from under the wing covers on each side
and a sixth pair at the tip of the abdomen
distinguish them from similar beetles. Adults
emerge from the ground and begin feeding
on plants in June. Individual beetles live
about 30 to 45 days. Activity is concentrated
over a four to six week period beginning
in July after which the beetles gradually
die. Japanese beetles can feed on about
300 species of plants ranging from roses
to poison ivy. Odor seems to be a very important
factor in the selection of a suitable food
plant. They usually feed in groups starting
at the top of a plant and working downward
and prefer plants exposed to direct sunlight.
A single beetle does not eat much; it is
group feeding by many beetles that causes
the severe damage. Adults feed on the upper
surface of foliage chewing out tissue between
the veins. This gives the leaf a characteristic
skeletonized appearance. They tend to do
little feeding on thick tough leaves. The
spread of the Japanese beetle infestation
is primarily the result of flight by the
adults. They can fly as far as 5 miles but
1 to 2 miles is more likely. Usually they
make only short flights as they move about
to feed. Local infestations spread as beetles
move to favored food and suitable sites
for egg laying.