A large and hairy bug with reddish memebraneous forewings and adomen marked with orange-red and black. The scutellum has a single whitish tooth, unlike the common R subrufus.  The corium veins have black dots and there is a pale median line down the pronotum.

other Rhopalus

Good photos showing scutellum and forewings are needed

Dry grasslands; associated mainly with Mouse-ear Chickweed

Locally distributed in mainly southern Britain

Rare.  

https://www.britishbugs.org.uk/heteroptera/Rhopalidae/rhopalus_parumpunctatus.html