Double Edged Sword

This gorgeous Rosemary Leaf Beetle was on the Lavender first thing this morning and I wasn't sure what it was, so I consulted Google who helped me identify it.
It apparently appeared in the UK in 1994 and is steadily spreading through the southern counties of England. Why the double edged sword? well, as beautiful as it is this beetle is rather sinister. It lives on Rosemary, Lavender, Sage and Thyme and kills the plants by eating the new shoots.
So, what should I do, it is against my nature to destroy anything intentionally but do I let IT destroy my Lavenders (that, I have to add, do need replacing anyway).
I've just checked the Lavender again and I cant see it now, perhaps I don't have to make a decision just yet!