If you spot this attractive but destructive invader in your garden over the autumn and winter months, the RHS would like to know.
Rosemary beetle Chrysolina americana feeds on aromatic plants including rosemary, lavender, sage, thyme and some related plants.
A native of southern Europe, rosemary beetle was first found outdoors in the UK at RHS Wisley in Surrey in 1994. By 2005 it was being found throughout London and the surrounding areas. Rosemary beetle is now widespread in England and Wales and has been found in parts of Scotland, Northern Ireland and the Irish Republic.
The adult beetles are 6 to 8mm long, with metallic purple and green stripes. The larvae are greyish-white with darker stripes and up to 8mm long. Both adults and larvae feed on the leaves of host plants, and flowers can also be damaged. The larvae can be found on the undersides of leaves from early autumn to spring. Adults can be found throughout the year.
They can be removed by hand-picking or by placing newspaper or an open upturned umbrella under the branches and tapping the plants.
If you see the rosemary beetle, the RHS would like you to complete its survey form, which takes just a couple of minutes. Find out more and record your sightings at