Angle Shades Caterpillar

Angle Shades Caterpillar

Observation - Angle Shades Caterpillar - UK and Ireland. Description: Caterpillar found aligned on a Dark Mullein plant which in itself is an observation in that it only finished flowering 2 weeks ago.Any ideas what caterpillar?

Caterpillar found aligned on a Dark Mullein plant which in itself is an observation in that it only finished flowering 2 weeks ago.Any ideas what caterpillar?