Do Japanese Beetles exist in your area? Did they just move into your area?
It seems that when Japanese Beetles first move into an area, they have a voracious appetite. The brown beetles have an iridescent green sheen and commonly found feeding on the newest growth of plants they like. The eat the tissue between the veins in the leaves leaving the leaves looking like brown lace.
The also eat the flowers of some plants like roses. Here you can see one in the lower left-hand corner feeding on the rose flowers.
What can you do to get rid of them?
Depending upon where you live, the beetles are first noticed late June or early July. Probably the easiest and most environmental way is to physically remove the bugs from the plants keeping in mind that they continue to hatch for 6-8 weeks. Pick off the plants and put them in a bucket of water with healthy squirt of dish soap to drown them.
Insecticides can be used and be careful to read the label for use on the plant you will be treating. You can also use insecticidal soap or neem based insecticides to help control them.
Some plants like roses that are huge magnets for Japanese Beetles, a systemic insecticide can be used. The beetles live for only about 60 days. Then they lay eggs in your lawn areas and they love watered lawns best.
The life cycle does allow for destroying the grubs in watered lawns and large expanses of turf areas like golf courses and watered parks. Japanese Beetles love watered turf areas best as the grubs feed on the roots of grasses. Birds, voles, and skunks will tear up your lawn areas to get at the grubs in the roots of your lawn.
Treating the grubs in the grass areas eliminates the beetles from hatching and causing damage to some trees & shrubs and roses. Typically, most grubs are best treated from now until late September, but timing of treatments is very important and you should contact your local ag extension office to see when that is in your particular area.