Wide range of plants. Spray with a solution of wheat flour, buttermilk and water. Spray with dormant oil spray. Grubs feed on grass roots, adults feed on a variety of plants. Grubs feed on grass roots leaving brown patches of lawn.
Hand pick adult beetles.
Keep the garden clean. Raise the pH of the soil. Larkspur is toxic to the beetles, so plant some nearby. Geraniums and smartweed repel the insects. Use commercial traps.