Toadflax Brocade Moth Calophasia lunula

The Toadflax Brocade moth colonised the UK in the 1950s and, as a breeding resident, mainly inhabits shingle and gravel areas near coasts in south and southeast England where there is access to the toadflax plant. Brown-grey with strong markings, wingspan in 26-32mm. On the wing between May and August, it is also seen as a migrant in July and August, sometimes in gardens.

Toadflax Brocade caterpillar The Toadflax Brocade caterpillar has yellow and black markings and grey sides.
Toadflax plant The toadflax plant
It eats toadflax plants (both the Common yellow, where it is camouflaged and the purple, where it is more visible) between June and September before spending winter as a pupa.
Many thanks to Colin Bell for the above photo of the caterpillar in his Hertfordshire garden in September.