The numbers of adults have been impressive in some cases. Trees, shrubs, vegetable plants, and fruit plants and trees have all been affected. Of course there are some plants that are favored feeding sites. These would include Japanese maple, Norway maple, Horsechestnut, Hollyhock, Flowering crabapple, Apple, Cherry, Peach, Rose, Mountain ash, Linden, and Grape. There are other plants that are seldom attacked such as Red maple, Silver maple, Boxwood, Flowering dogwood, Euonymus, Ash, Oak, and Lilac. Of course you need to take this list with a grain of salt since I have sprayed large numbers of beetles on the seldom attacked plants this weekend.

My rule of thumb is protect fruits, vegetables, valuable ornamentals, and new transplants. Most are spraying Orthene, Sevin, permethrin, or bifenthrin. The frequency is what gets us sometimes with sprays needed at least every week in most cases. To dispel a common myth, once you have the beetles you will always have them. They do not occur on an infrequent basis like periodical cicadas, nor it is "just a year to have them." They have expanded their range, and you are now in it.