Answer: Based on your description it is a bit difficult to make an identification but it is about the time of year to see the plump, irridescent, blue and greenish, flying, Japanese beetles on plants, and two of their favorites are roses and grape foliage. They can be hand picked (knock them into soapy water) in the evening or the morning when they are slower moving, or they can be deterred with a spray containing neem, or they can be treated as a last resort with carbaryl. Please be sure to carefully read and follow all of the label instructions if you opt to spray. Although pheromone traps are also available, in my experience they seem to attract as many to the area as they catch.
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