We had asian beetles when we moved in 7 years ago...everywhere. Now we see maybe 2 dozen a year.
Go to your farm/home store, wal-mart, etc and get a pesticide that has Diazinon in it. (can be hard to find) It is a full strength chemical. You hook the bottle up to your garden hose and it mixes it with water as you spray.
Spray the outside of your house around all window and door frames. We did this fall and spring for 2 years (4 applications) and have seen an amazing drop in beetles.
I am not a big fan of chemicals but it had to be done.