Question
What would you recommend to help eliminate Japanese beetles.  Last summer they attached themselves to my purple sand cherries

Answer
If you are not dealing with many Japanese beetles, you can use hand removal.  The beetles are less active in the morning and can be picked up and dropped in a bucket of soapy water.  

I do not recommend Japanese beetle traps that use pheromones.  Unless they are being used over a large area (ie. throughout a neighborhood) they usually attract more beetles than are killed.

The only way to truly control a large number of beetles is with insecticides.  There are many products available at your local garden center.  You should look for products containing acephate (Orthene), carbaryl (Sevin), bifenthrin, cyfluthrin, deltamethrin, lambda‐cyhalothrin, or permethrin.  You can also use imidacloprid (e.g., Bayer Advanced Tree & Shrub Concentrate) but the application should be made at least 20 days prior to Japanese beetle adult activity. When adult activity is heavy, insecticide sprays may be needed every 5 to 10 days. In general, soil applications of insecticides to target larvae will not reduce adult Japanese beetle populations because they colonize from surrounding areas.

Good luck!