They also have an overwhelming appetite for your favorite rose.
Adults feed in herds on many deciduous trees, shrubs and vines
such as linden, Japanese maple, sycamore, birch, elm and grape.
They generally do not feed on dogwood, forsythia, holly and
Japanese beetle adults feed on flowers and fruits and
skeletonize leaves by eating the leaf tissue between the veins.
Severely damaged leaves turn brown and fall from the trees. They
look like brown lace. Feeding is normally in the upper portions
of trees. Beetles prefer plants in direct sun, so heavily wooded
areas are rarely attacked.
Adults can be with us until mid-August. The life cycle is
similar to a June bug. After mating, females lay eggs in turf,
and the eggs hatch into grubs in August. Grubs feed on plant
roots until cold weather drives than deeper into the soil.
Adults emerge in summer of the following year.
The bacterial control, milky spore sold as Doom or Grub
Attack, is frequently recommended to control Japanese beetle
grubs. In our area milky spore is generally not recommended,
since it controls only Japanese beetle grubs and not other lawn
grubs. Also, Japanese beetle grubs must already be infesting the
turf for milky spore to work effectively. Pesticides commonly
used for lawn grub control will also control Japanese beetle
Controlling Japanese beetle grubs does not significantly
reduce the number of adult beetles the following year. The
beetles are good fliers and easily fly a couple miles in a
single flight. Once a small group of beetles establishes itself
in an area, they attract others by giving off pheromones for
mating and feeding. Evidence suggests that adult beetles are
attracted to previously damaged leaves. Therefore, reducing
feeding damage now can result in less feeding damage in the
Generally pesticide sprays of cabaryl sold as Sevin can
reduce damage for up to two weeks, but four to seven days is
more likely. Sevin is toxic to bees. Synthetic pyrethroids can
also be effective but tend to break down quickly with extreme
heat. These would include permethrin and bifenthrin. The
Japanese beetle repellent made from Neem has not been shown to
be effective. Picking beetles off by hand every couple of days
may be just as effective as spraying. When disturbed, the
beetles fold their legs and drop to the ground. Covering plants
with floating row covers can protect prized roses and ripening
fruit. Japanese beetle traps are not recommended since they can
actually increase damage by attracting more than they kill.
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A number of birds, such as grackles, cardinals and meadowlarks,
feed on adult beetles. Two native predator insects and a couple of
introduced parasites may help to keep Japanese beetle populations in
check. Protect natural enemies by keeping the use of conventional
pesticides to a minimum. Although damage looks devastating, Japanese
beetle feeding rarely kills plants. Therefore, confine control of
beetles to shrubs and small trees near main building entrances and
other important landscape locations where damage is obvious.
Protecting a prize rose bush or a newly transplanted linden tree is
a good idea. The U of I Arboretum decided not to treat anything
three years ago and didn't lose any plants.
Father's Day is a good benchmark for planting pumpkins for
carving or fall decorations about Halloween. Earlier planted
pumpkins are great for display in September and early October but
tend to be of poor quality come mid-October.
Vining pumpkins need at least 50-100 square feet per hill, with
the larger pumpkins requiring the larger area. Hills should be five
to six feet apart, and rows of hills should be 10-15 feet apart.
Each hill should have about four seeds per hill, planted about an
inch deep. The miniature varieties such as the Jack-Be-Little are
sometimes grown in rows with seeds planted every eight-12 inches,
then thinned to about two feet apart in the rows.
Fall decoration pumpkins should be cut from the vine before the
vine dries in order to have a good stem attached to the pumpkin, but
after the color is acceptable.
[Text from file received from
Fulton, University of Illinois Extension,
Logan County Unit]