One of the world's most invasive insects is arriving in the UK in record numbers. The harlequin ladybird (Harmonia axyridis) has been sweeping through England at an alarming rate since its arrival in 2004 and observations from this autumn show that the ladybird is arriving in greater numbers than ever.H. axyridis adult and pupa © Bev Wigney

This harlequin is a highly invasive alien species which forms a major threat to native ladybirds and other insects including butterflies and lacewings through eating eggs and larvae.

A major project run jointly by the Centre for Ecology & Hydrology (CEH), Anglia Ruskin University and University of Cambridge has been recording observations of harlequin ladybird sightings over the last 24 months. Recent records show that swarms of harlequins have hit the south coast of England, from Devon to Kent. Thousands of harlequins are reported at locations in the south, particularly in Sussex, Hampshire and the Isle of Wight. The insect has now also reached Wales and has got as far north as North Yorkshire.

Peter Brown, project officer for the survey based at CEH's research site at Monks Wood, commented: "It is vital that we continue to monitor this aggressive alien species as well as the UK's 45 native ladybird species, so that we can assess the impact of the harlequin on native insects."

Harlequins are native to S.E. Asia and were introduced in continental Europe to control pest insects such as aphids. They gather in large groups (often thousands of ladybirds) to spend the winter, often in or on buildings, so can also cause a human nuisance.


Members of the public can record Harlequin ladybird sightings on the website.