Wool sower gall wasp
The wool sower is a tiny dark brown wasp, only about 3 millimetres long. It is famous for what it makes the oak tree grow: a round, fluffy white ball that looks just like cotton wool. Its babies live inside that ball.
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Fun facts
It lays its eggs only on white oak trees, and only in spring.
The woolly ball starts out white and later changes colour.
Inside the ball are little hard bits that look like seeds, but they are really made of plant material.
Scientists still do not know what the gall of its other generation looks like.
Most asked questions about Wool sower gall wasp
?What is the white fluffy ball on an oak?
It is a gall made by the wool sower wasp. Its babies grow up safely inside it.
For bug experts
- Scientific name
- Callirhytis seminator
- Group
- Wasps and hornets
- Family
- Cynipidae
- Classification
- Insecta > Hymenoptera > Cynipidae
- Lives on
- North America
- Also known as
- Wool sower
Where the facts come from
- Callirhytis seminator (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
- Picture by (c) Hila Taylor, some rights reserved (CC BY). CC BY 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.
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