Bug Wiki
Sticker of Ram's horn gall wasp
Bug card No. 3483 of 4,939

Ram's horn gall wasp

Andricus aries
Name means: “the ram, because its galls look like a ram's curly horn”
Eats: PlantsWasps and hornetsForests and woods6 legs

The ram's horn gall wasp is a tiny wasp that makes oak trees grow strange shapes. Its eggs make the tree grow a long, curved lump called a gall, which looks like the horn of a ram. The baby wasp lives safely inside it.

Lives in
Europe, first in the east and now also in the west and in England, on oak trees
Top speed
about 22 km/h (14 mph)
Flying, estimate
What does it eat?
Its larva grows inside the oak gall and feeds on it from the inside.
For real!Photo of Ram's horn gall wasp
Picture by Andy Mabbett. CC BY-SA 4.0, via Wikimedia Commons.

How fast is it?

cool stuff

Fun facts

1

The gall is green at first. Later it hardens and turns brown.

2

It lays its eggs on several kinds of oak trees.

3

It used to live mostly in eastern Europe but has spread west. In England it was first found in 1997.

4

Sometimes other tiny insects move into its gall, and then the gall can grow into odd shapes.

you asked

Most asked questions about Ram's horn gall wasp

?What is a gall?

A gall is a lump that a plant grows around a little insect egg or larva. For this wasp, the gall grows on oak trees and is shaped like a ram's horn.

For bug experts

Scientific name
Andricus aries
Named by
Giraud, 1859
Group
Wasps and hornets
Family
Cynipidae
Classification
Insecta > Hymenoptera > Cynipidae
Lives on
Europe

Where the facts come from

  1. Andricus aries (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
  2. Picture by Andy Mabbett. CC BY-SA 4.0, Wikimedia Commons. The sticker of this bug is drawn from this picture.

If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at [email protected] and we will fix it.

Bug Wiki honey jar For grown-ups: Bug Wiki is free, with no ads and no tracking. A small tip helps keep it online.Leave a tip

More from the same group: Wasps and hornets

Also at home here: Forests and woods

Honey jarfor grown-ups