The description in the catalogs and instructions that come with the traps should give you and idea. I don’t recall the particulars.
We just had one trap that we put close to the Rosa Rugosa, since the beetles were totally swarming the rose hips. The other stuff they haven’t really bothered since we put out that one trap.
I’m thinking the Rosa Rugosa may be sort of like a “trap” plant having such an attraction that they forget about the other stuff, but that is sheer speculation on my part.
I have a rosa rugosa too and its the only thing in my yard that had Japanese beetles. I just hit them hard with a hose in the evenings and that seems to keep the numbers down. Plus we have a lot of insect eating birds they help too.
Thanks for your tips.