Chasmias lugens ?

Observation - Chasmias lugens ? - UK and Ireland. Description: About 20-22mm ,all black but with a white spot on each side of thorax and one spot on back of thorax ,nectaring on Angelica.
About 20-22mm ,all black but with a white spot on each side of thorax and one spot on back of thorax ,nectaring on Angelica.