Theo Asir wrote:

Grubs typically chew the leaves
when they become beetles
and this is very notice-able.

They do not seriously affect
the root system.

I believe japanese beetle grubs are not picky about the type of roots
they eat and will eat the roots off of roses as well as grass. As
someone here (sorry I forgot who!) has already recommended, Milky Spore
is a good preventitive. It was easy to put down and all I was told to
do was wash it into the soil with water afterwards. It provides optimim
protection in aproximately three years and has been recorded that the
protection can last up to 18 years.

I'm currently on a campaign to get all my neighbors to put some down to
help cut down on the japanese beetle population. At roughly $20 for a
can that will do 2500 square feet, I think in the long run, it's pretty
cheap.

Susan
s h simko at duke dot edu