Rosemary Beetle Chrysolina americana
Despite the scientific name suggesting a New World origin this species apparently originated from southern Europe. It was first found living in the wild in the UK in 1994 but rapidly spread.
I don't have a good track record of keeping Rosemary alive in my garden (the beetles are certainly not to blame) but as it can also get on Lavendar I periodically check this for beetles. No such luck but this one was attracted to my moth trap.
Rosemary Beetle Chrysolina americana, North Elmham (Norfolk, UK), 31st May 2024