Where does your beetle come from, Ben? There is a European subspecies Gaurotes virginea thalassina (Schrank, 1781) that is also with red pronotum, while it is Gaurotes virginea aemula (Mannerheim, 1852) in China, Kazakhstan, Mongolia and East Russia.
Hi Vitali Yes, you are correct it is indeed Gaurotes virginea thalassina. I have just got the specimen down from my loft and the data label reads : 27-07-96 - Becice - Czech Republic.