Invasive Ladybird Threatens UK Species

A new ladybird has arrived in Britain. This is not just any ladybird, this is the Harlequin ladybird, the most invasive ladybird on Earth.

A new ladybird has arrived in Britain. This is not just any ladybird, this is the Harlequin ladybird, the most invasive ladybird on Earth.

There are 46 species of ladybird resident in Britain and the recent arrival in 2004 of the Harlequin ladybird is a major threat to many of these. It is also a deadly threat to many other insects, including butterflies and lacewings.

The Harlequin ladybird is an extremely voracious predator that easily out competes native ladybirds for food. It is so successful that while native ladybird numbers dwindle the Harlequin ladybird flourishes. When their preferred food, of green fly and scale insects, is not available the Harlequin readily preys on native ladybirds and other insects such as butterfly eggs, caterpillars and lacewing larvae.

Introduced from Asia into North America for biological control of aphids on crops, the Harlequin ladybird has swept across the US, quickly becoming by far the most common ladybird. In the last decade its catastrophic increase in numbers has threatened native North American ladybirds and other aphid predators, many of which are plummeting alarmingly as the Harlequins consume their prey.

The Harlequin ladybird is also partial to overwintering inside houses in huge numbers where their defecations destroy upholstery, curtains and wallpaper. Despite this unwelcome and well-publicised take-over of America by the Eastern invaders, Harlequin ladybirds are still sold in continental Europe by bio-control companies, and it now roams across France, Belgium and Holland, with numbers soaring annually.

The Harlequin Ladybird Survey is keen to monitor the distribution of these ladybirds in the UK. If you have spotted a Harlequin, please record it with the survey so that checks can be made on it’s spread across Britain.