The harlequin ladybird was introduced to North America in 1988, where it is now the most widespread ladybird species on the continent. It has already invaded much of northwestern Europe, and arrived in Britain in summer 2004. The harlequin ladybird (Harmonia axyridis) is also known as the Multicoloured Asian Ladybird and the Halloween Ladybird. It has a very variable appearance, which can make it difficult to tell apart from our native ladybirds.
I submitted this siting to The Harlequin Ladybird Survey website. This is H. axyridis succinea.