Japanese Beetle vs Emerald Ash Borer
Japanese Beetles and emerald ash borers are easy to mix up at a glance, but a few details separate them quickly. Here is how to tell which one you found and what, if anything, you should do about it.
Quick answer
Check for this first. A Japanese beetle has metallic green head and thorax with coppery wing covers, while an emerald ash borer has bright metallic emerald green body.
Side-by-side comparison
| Japanese Beetle | Emerald Ash Borer | |
|---|---|---|
| Group | Beetles | Beetles |
| Scientific name | Popillia japonica | Agrilus planipennis |
| Size | 10–15 mm | 8–14 mm |
| Colors | Green, Metallic and Brown | Green and Metallic |
| Legs | 6 legs | 6 legs |
| Wings | Yes | Yes |
| Bites or stings | No | No |
| Risk | Nuisance | Nuisance |
| Key feature | Metallic green head and thorax with coppery wing covers | Bright metallic emerald green body |
Key differences
- Color: Japanese Beetles are green, metallic and brown; emerald ash borers are green and metallic.
- Where found: look for Japanese beetles in gardens and on plants and in lawns and grass; emerald ash borers turn up on trees and shrubs.
- Signature feature: Japanese Beetles: metallic green head and thorax with coppery wing covers. Emerald Ash Borers: bright metallic emerald green body.
How to identify Japanese beetles
A metallic green beetle with copper-brown wing covers that skeletonizes the leaves of roses, grapes, linden and hundreds of other plants. Its white grubs feed on grass roots in lawns.
- Metallic green head and thorax with coppery wing covers
- Five tufts of white hair along each side of the abdomen
- Feeds in groups, leaving lace-like skeletonized leaves
How to identify emerald ash borers
A slim, bullet-shaped, metallic green beetle whose larvae tunnel beneath ash tree bark. It has killed hundreds of millions of ash trees across North America.
- Bright metallic emerald green body
- Coppery-red upper abdomen visible when the wings open
- D-shaped exit holes about 1/8 inch wide in ash bark
Which one is more dangerous?
Neither is more dangerous than the other; both are rated nuisance on our scale.
Japanese beetles do not bite or sting people; the harm is to plants and turf. Emerald ash borers are harmless to people but lethal to untreated ash trees.
Where and when you'll see each
Japanese Beetles turn up in gardens and on plants and in lawns and grass, mostly in summer. Emerald Ash Borers turn up on trees and shrubs, mostly in summer.
Where you found the bug is itself a strong clue, since these two rarely share the same spots.
What to do if you find one
Japanese Beetles: Hand-pick beetles in the early morning and drop them into soapy water. Read the full removal guide for more.
Emerald Ash Borers: Check ash trees for canopy thinning, bark splits and D-shaped holes. Read the full removal guide for more.
Biology: beetles
Beetles go through complete metamorphosis: egg, larva (grub), pupa and adult. The larval stage often does the most feeding and damage, and it can last from a few weeks to several years depending on the species. Adults protect their flight wings under hard wing covers called elytra, which is why most beetles look armored and meet in a neat line down the back.
Frequently asked questions
What is the main difference between Japanese beetles and emerald ash borers?
Color: Japanese Beetles are green, metallic and brown; emerald ash borers are green and metallic.
Which is bigger, a Japanese beetle or an emerald ash borer?
Japanese Beetle: 10–15 mm. Emerald Ash Borer: 8–14 mm.
Do Japanese beetles or emerald ash borers bite?
Japanese Beetles do not bite. Emerald Ash Borers do not bite.
Where are they usually found?
Japanese Beetles: in gardens and on plants and in lawns and grass. Emerald Ash Borers: on trees and shrubs.