For a few years I had expected the arrival of this brightly colourful leaf beetle to my garden. It has followed its food plants, which include not only Rosemary but Lavender, Sage, Thyme and related aromatic plants. As other species accidentally introduced in a non-native range, it has expanded quickly in the UK from its presumably initial introduction point at an RHS garden in Surrey in 1994. By 2005 it had spread throughout greater London and nowadays it has spread north to Scotland (see the NBN Gateway map
here).
Today, four adults were feeding on a single lavender plant in the garden. I couldn't see any others in the other lavenders, so I wondered if they were the offspring of last year arrival.
The adult and larvae feed on leaves and flower buds and they can quickly defoliate bushes as the summer progresses.
More information
RHS page on Rosemary Beetle.
