Japanese Beetle

• Skeletonized leaves with only the veins remaining — a distinctive lacy pattern
• Metallic green and copper-brown beetles, about 1/2 inch, feeding in groups
• Damage concentrated on the top of the plant canopy in full sun
• Flowers and soft fruit may also be fed on
• Adult feeding peaks in late June through August

Adults emerge from the soil in late June and July and are highly mobile — they can fly a mile or more to find host plants. They feed for four to six weeks, then lay eggs in turf grass. Larvae (white grubs) develop in lawns through summer and fall, overwintering deep in the soil. Pupation occurs in late spring. The beetle is established across the eastern US and continues to spread westward.

1. 01Hand-pick adults into a jar of soapy water in the early morning — they are sluggish and easy to knock off
2. 02Avoid pheromone traps: research consistently shows they attract more beetles than they catch, increasing damage near the trap
3. 03Kaolin clay (Surround) applied to foliage can deter feeding
4. 04Neem oil (azadirachtin) acts as a feeding deterrent when applied before beetles arrive
5. 05Row cover can protect vulnerable crops like green beans during peak feeding weeks
6. 06Apply milky spore or beneficial nematodes to lawns to target larvae — results take one to three seasons to build

If beetle pressure is severe for multiple seasons and you're seeing plant loss, an extension specialist can advise on whether your area has parasitic flies (Istocheta aldrichi) becoming established — a natural control that is slowly spreading in the Northeast.

• Japanese Beetle— University of Maryland Extension
• Japanese Beetle in the Home Garden— Clemson Cooperative Extension