This extremely common bug is found throughout the UK on a range of plants, particularly nettles.
Although the ground colour varies from pale olive-green to almost black, the head and front of the pronotum are usually dark, as are the 1st and 2nd antennal segments. The dark margins of the hind femora are a very useful identification feature; these are also present in late instar nymphs. The spines on the hind tibiae are equal to or longer than the tibial width and generally arise from black spots. The pronotum and forewings are covered in dark hairs.
Seen in the gardens of Chiswick House in July 2020