One could certainly try using Sevin. But, the following quote is also from the site that I referenced above.
Q. Mike: I am being overrun; I used Sevin; they laughed at it. I mixed it stronger; they laughed louder. I have dogs and am not comfortable spraying insecticides all the time.
And, from the following site, there is the information below.
Japanese Beetles
Control Methods for Adult Beetles
Management of Japanese beetles is at times difficult and other times relatively easy. Correct timing and economical control measures are very important. If you want to control the adult Japanese beetle, the time to do this is when they are actively feeding on leaves, such as roses and crape myrtles. There are several different insecticides that can be applied to the plant leaf surface to assist in controlling the adult Japanese beetle, Select only one product to apply at a given time. Sevin 50WP or Orthene are recommended for homeowner use on trees and shrubs. The foliage of ornamental plants can be protected by dusting or spraying with one of the following pesticides:
Sevin 50W
Diazinon 25EC
Pyrellin EC
The use of Sevin or other insecticides might also be harmful to other living things which might be beneficial to a garden in addition to it's toxicity to humans. Please see the information on the following link concerning that.
Can I use Sevin? - Vegetable Gardening Forum - GardenWeb