Japanese beetles
 Japanese beetles are 1/2 inch long and
are metallic blue-gree with coppery wing covers. The larvae are 3/4"
long and are white and C-shaped. They are a serious invader pest. The
beetles arrived in 1912 on Japanese Iris bulbs and they were first noticed
in 1916 in New Jersey. They have been slowly moving west ever since. Japanese
beetles were first noticed in the Twin Cities in the late 1980's on nursery
stock that was planted in the area. Lyndale park, including the Lake Harriet
Rose Garden and the Robersts Bird Sanctuary were infested the summer of
2001. They do not fly at night but they can be seen flying around during
the day.
Problem
Japanese beetles feed in masses and severely damage landscape, plants
and turf. Adults feed on over 275 plant species including all deciduous
tree fruits, many small fruits, ornamenatal shrubs, vegetables, grasses,
weeds, and some row crops. Damaged leaves may be skeletonized or they
may be almost entirely defoliated. They feed and hide in the center of
flowers. Roses are a favorite food. Adults are highly mobile and often
reinvade favored hosts after a pesticide application.
Larvae feed on roots of grass, herbaceous plants and nursery stock. The
grubs can be serious pests of lawns, turf grasses and nursery stock. Racoons
and Canada Geese move into areas rich with Japanese Beetle grub infestations
and dig up the turf to find them.
Damage Control
The grubs are most easily transported to other areas in the soil surrounding
the roots of balled and burlapped plants. Quaranteens are used to restrict
the movement of potentially infested plant materials.
If you notice a lot of beetles flying around, cover smaller or more valuable
plants with floating row covers.
Destroy beetle eggs in your lawn by allowing it to dry out well between
waterings.
In late spring and early fall you can kill grubs by aerating the lawy
with spiked sandals.
On cooler days, the beetles sit on plants and can easily be picked off
and destroyed.
Traps are available and are effective for very large areas such as a
golf course. In small backyardsthey are less effective because they attract
beetles from the surrounding area.
Chemical insecticides, in the form of granules or sprays, can be effective
in controlling larvae in soil and turf. Insecticidal sprays can be applied
to adult beetles.Treat your lawn with milky spore disease or with parasitic
nematodes in early spring or early fall.Or spray with neem. In the evening
you can even knock them off your plants into a bucket of soapy water. |
