Eucalyptus Gall Wasp

Ophelimus spp.

Eucalyptus Gall Wasp

Ophelimus maskelli galls on Eucalyptus by Giancarlo Dessì (CC BY-SA 3.0)
1 of 2
A close up of a tree leaf infested with Ophelimus Eucalyptus gall wasp
Ophelimus maskelli galls on Eucalyptus by Giancarlo Dessì (CC BY-SA 3.0)
1 of 2
Eucalyptus Gall Wasps are tiny fly-like wasps. They're parasitic wasps, which means they require a living host to reproduce successfully. Ophelimus spp. are solitary; unlike yellowjacket wasps who live in social nests with multiple individuals. They use the leaves of Eucalyptus to lay their eggs. Eucalyptus plants respond to infestations by producing abnormal bumps, called galls. The wasp's larvae develop inside the gall until mature, emerging as adult wasps. Ophelimus spp. is most damaging in Eucalyptus plantations, and less so in gardens. Usually, the first symptom noticed is infested leaves falling prematurely.


Cause brown galls, or raised bumps, to develop on Eucalyptus.


Adults: The wasps are so small it's unlikely you'd see them. They are completely black and are smaller than 1mm, they can easily be mistaken for small flies. Galls: Identify parasitic wasps using the galls. Look out for raised swellings on both sides of Eucalyptus leaves. These swellings are around 1mm wide and pink-brown or sometimes they're yellowish-green. There will be a tiny grub in each gall.


Red-brown or greenish-yellow bumps on Eucalyptus leaves. Infested leaves fall prematurely.











Parts of Europe, Asia and Africa, Australia

Biological treatment

This wasp will not impact the longterm vigour of trees, but the galls it produces may be unsightly. To avoid reinfestation, pick up and destroy infected leaves which have fallen to the ground and this may help control numbers the following year.


Be the first to download the app

Help us build a place where community meets knowledge. Try it out and let us know what you think.
Download on the App StoreGet it on Google Play

What is Candide?

Candide has everything for plant lovers – buy plants from independent sellers and book tickets to visit inspiring gardens near you. Identify plants in seconds from a single photo and learn how to care for them with our in-depth guides.


Learn how to care for your plants and share your growing successes on Candide’s free app for your phone or tablet.

Download on the App StoreGet it on Google Play

Germinated in Bristol © 2021 Candide