around 5cm in length
pronotum violin shaped black
elytra bronze with three distinct parallel indentations along its back
I found it this afternoon in a clump of couch grass on my allotment
Not sure, but from the size it seems most likely to be one of the Carabus species, although even they are usually below 4cm long. Can't think what else would fit though. Can you get a photo?
Entomologist and biological recorder