They say the traps actually attract the beetles to your yard and aren't really recommended.
How many rose bushes are you taking care of? I take a larger bowl of dish soap and water. I make sure there is lots of foam on the top. I take tweezers - I like the extra long ones for making models but any will do - I position the bowl under the flower and knock the beetle off, into the bowl. If he is stubborn, I will grab him with the tweezer and dunk him. This works for earwigs and any other offending beetles too.

Take the traps and put them as FAR AWAY from the roses as possible. I'm talking the most remote corner of your property. I don't use them, I find they are just an invitation to dinner, but others have had success.

Do what loretta said.

Get Milky Spore to spray on the lawn to rid yourself of the grubs (your neighbors will have grubs too, but it helps).

Insecticide option is imidicloprid (called "Merit", products are by Bayer Advanced), but you don't want it on your edibles.

I'm having the same problem...my climbing roses look like shredded wheat! I also hung the JB traps and I swear there are more JB's now than before!>(
What time of year should the milky spore be applied?

I live in Burlington and have a garden with 15 rose bushed and 3 ornamental fruit trees. I have had almost no JBs this year I have had years when they were bad. I have tried traps and have used Milky Spore. I still think the best thing is hand picking with a bucket of hot water with dish soap I hold the bucket under the beetles and nudge them off.

I still have lost patches of grass to JB grubs. The turf dies as they eat the roots I pull it off to expose them and pick them up and throw in a similar bucket.

I listen to this garden show from Chicago. Link below.

Someone asks a beetle question (like your's) and the horticulturist pooh pooh's traps and milky spore.

The house I work at in Princeton has over 100 rose bushes and the gardener has 9 traps near the bushes. There are loads of beetles on the bushes. He also sprays Sevin like it is water and I don't see any bees in the garden. My point is that there is no silver bullet. For me black spot is a worse rose affliction.

Best wishes.

Here is a link that might be useful: Focus 580

I used the Bayer Advanced (Merit) this year and have seen only a few beetles, which is A LOT less than past years.
This is what Rutgers Extension told me....
"As far as the grubs in your lawn you should treat with Merit between June15th and July 15th in order to rid your lawn of both the larvae and the adults. Any earlier or later you may only get one or the other."