I don’t really interplant, but I try to keep an insect friendly garden, never spray pesticides, and occasionally purchase beneficials to add. Most likely, our insect life is pretty different due to our location and climate, but I have noticed a few things that might be helpful.
Predatory wasps seem to loooove my celosia. Definitely their favorite.
Regular wasps are pretty happy to eat caterpillars also. I’ve discovered over the years that if I’m having a minor caterpillar invasion I can snip several caterpillars in half on the plant to attract wasps to the location. It’s kind of fun to watch. (Sorry if that’s too grotesque!)
The only thing that really seems to help much with Japanese beetles seems to be to remove other attractive food sources and bag blooms. I had a rose nearby that they loved and have had less of a problem with them on dahlias since I took that nearby rose bush out.