Why would anyone send out invitations asking Japanese beetles
into their yard? They’ll
eat almost everything there. Still, many Georgians keep inviting
them year after year.
“People sometimes try to use commercial traps to control
Japanese beetles. Don’t ever
do that,” said Beverly Sparks, an entomologist with the
University of Georgia
Extension Service.
The traps will catch the landscape-munching beetles, all right.
But the pheromone they
use to call the bugs into the trap will also attract them into
your yard. That’s the
problem.
“Don’t try to use traps for control. They’ll just call more
beetles into your yard,”
Sparks said. “Traps are good for monitoring populations and
letting you know when the
beetles begin to show up. But once you start catching some, you
need to remove the
traps.”
Japanese beetles are metallic green, thumbnail-size bugs with
coppery wings. They
have a row of white spots around the margins of their wing
covers.
You don’t often see one alone. “They usually appear in large
numbers,” Sparks said.
The adult beetles eat the leaf tissue between the veins in a
number of landscape plants.
Their favorites are crape myrtles, plums, cherries and peaches.
But they love roses,
too.
“They’re not really very picky,” Sparks said. “They feed on a
wide range of landscape
plants, and in large numbers they can do some significant
feeding damage.”
Once Japanese beetles show up in your yard, the most effective
thing you can do is
treat infested plants with an insecticide.
Sparks recommends Sevin and said it’s best to spray on a liquid
formulation. “It’s the
most effective,” she said, because it allows you to cover the
leaves better.
“The product breaks down in just a few days in intense sunlight
and high heat,
though,” she said. “So you’ll need to spray the foliage again
about once a week
throughout the period the beetles are active.”
When beetles reappear, the problem isn’t that the Sevin isn’t
working. It’s just that new
bugs continue to migrate into the area.
“Japanese beetles are very mobile, and they can fly long
distances,” Sparks said.
“Flights usually last six to eight weeks, so you have to keep
treating the foliage they
feed on.”
If you don’t like the idea of using chemicals in your yard, pick
the beetles off by hand,
or shake them off over a bucket of warm, soapy water. “Japanese
beetles aren’t all that
hard to kill,” Sparks said.
Remember that the beetles will keep coming. Whichever method you
use to get rid of
them, you’ll have to keep doing it.
Just don’t keep those pheromone traps out in the backyard. Or if
you do, you may want
to book a bug band and put in a tiny dance floor — it’s going
to be a long beetle party
out there.
