Mid-Atlantic Gardening: Yardening July 2015, 3 by Gitagal

Gitagal wrote:
I have a couple general Yardening questions....

My huge Kopper King Hibiscus is starting to bloom. So far--2 blooms--
but it has many buds ready to pop. of course--the Jap. Beetles are all
there waiting.
Today--there are the 1st 2 blooms--and each one already had holes
in them from the beetles. I have been picking the beetles off with a cup of
soapy water--but when all the KK buds are open--that will be impossible.
Been picking them off my roses--or what is left of them. They are totally trashed!

My question is:
Can I spray the unopened bloom buds with something that will deter the beetles
from munching on them? I have ALL kinds of products--would a systemic stop them?
How about Horticultural Oil? Or--how about some insect spray? I have them all!

1--Kopper King Hibiscus with the first bloom--already a hole in it!

2--Bloom close up...

3--These are the bloom bud-clusters. As you can see, even the foliage
is already chewed up. The beetles just wait for the blooms to start opening--
and they are at it.

I need some ideas of what would work the best. Thanks, Gita