Japanese Beetles
Half-inch beetles with a metallic-green head and copper wing covers, feeding in groups in full sun from late June through August. They skeletonize leaves, eating the tissue and leaving the lace of veins behind.
Pest checklist
Four things to look for. If most of them match what you are holding, you are in the right place.
What gets rid of them
Gentlest option first. For most backyard cases the first one is enough, so try these in order and stop as soon as it works. If you do spray something, the product label tells you how — please read the notice further down.
1Hand-pick into soapy water
Early morning while they are sluggish: hold a bucket of soapy water under the branch and tap. Truly effective at garden scale.
Try this first2Row cover during peak flight
Physical exclusion for crops that do not need pollination during the six-week beetle season.
floating row cover garden3Beneficial nematodes for the grubs
Water Heterorhabditis bacteriophora into moist lawn in late summer to kill the grubs. Skip milky spore — university trials have not found any benefit from it.
beneficial nematodes grub control heterorhabditis4Skip the traps
Bag traps draw beetles from blocks away and most never reach the bag. Extension guidance is consistent: they make yards worse, not better.
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Which plants get japanese beetles
Every plant we cover that gets japanese beetles, grouped by type — tap any one to open its page. A note beside a plant came from that plant’s own entry, because the same pest can be a minor nuisance on one plant and a serious problem on another. Plenty of plants we do not cover get it too.
trees4
shrubs8
vines2
perennial1
biennial1
Plant families hit hardest
Related plants often share the same problems, so if one plant in a family has it, check the others. The largest group here is Malvaceae, with 5 of the 21 affected plants.
- Malvaceae5 plants
- Rosaceae5 plants
- Asteraceae2 plants
When to treat
Start the day the first ones appear, late June here, and keep knocking them down daily into August.
On specific plants
- Growing
- Monitor for Japanese Beetles (manual remove). SWD: Insecticide as berries turn purple if detected.
Timing only — the label is the law
This page tells you when to watch for japanese beetles and when treating is worth considering. It is not a recommendation to apply any particular product. Read and follow the product label before you spray — under federal law the label is the legal instruction, and using a pesticide against it is illegal.
- Check the pre-harvest interval. Every product that’s cleared for an edible crop sets a minimum number of days between spraying and picking. Find it on the label before you spray anything you intend to eat.
- Check the re-entry interval before you or anyone else works in the treated area again, and use the protective equipment the label names.
- Confirm the product is registered for your crop in your state. This page groups many different crops together, and a product legal on one of them is not legal on all of them — state registrations differ too. Your state pesticide agency or local extension office can confirm both.
- Rates and mixing instructions come from the label, never from us. We don’t publish them because they differ by product and formulation.
Other problems on the same plants
If a plant gets japanese beetles, these are the problems it most often gets as well, so they are worth checking for while you are out there. They tend to appear together; one does not cause another.