The cynipid wasp Phanacis hypochoeridis causes galls to form in Cat's-ear (Hypochaeris radicata). This takes the form of an elongated swelling, usually in the main stem of the plant, but sometimes in the flower stalk or petiole, succulent at first, later hard often wrinkled inside – up to 50 chambers, each with a yellowish-white larva.

It is a unisexual species, with males rare or absent; the females reproduce by parthenogenesis

Gall  Adult

Where Cat's-ear occurs.

Summer and autumn.

Widespread but uncommon or under-recorded in Britain.

Status in Leicestershire and Rutland not known.