Thistle Gall (Cavenham Heath NR)

The Gall is Caused by the Thistle Gall Fly – Urophora cardui  which
lays its eggs on Creeping Thistle (Cirsium arvense). After hatching, the larvae burrow into the stem of the plant and form a gall (or swelling).

Thistle gall caused by a gall wasp

Thistle gall caused by a gall wasp

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