These are oriental beetles. Closely related to the Japanese beetle, they are active this time of year and will feed on a variety of plants. Your best option is to handpick them off plants. Unless it's a hot day, they are not the best fliers. 

Spraying flowers to control the beetles is not recommended. The beetles spend their larval life stage as grubs in the lawn. In August or September, check beneath areas of your lawn for possible grubs. If there are 15-20+ per square foot, that is a sign you might need to treat the lawn to control the beetles.