A new ladybird has arrived in Britain. This is the harlequin ladybird,
Harmonia axyridis, the most invasive ladybird on Earth.
It has been introduced into a number of countries as a biological control agent for greenfly because of its voracious appetite for aphids. Unfortunately it has been discovered that once it has eaten all the aphids in an area it will start to eat other insects, including the ladybirds of the country it has been introduced into. Although most ladybirds are cannibals a natural balance has been developed between native species, however, the harlequin also has a chemical defence which deters other ladybirds from eating it. In it's original home in Asia the harlequin has natural predators and diseases which keep the population down, but it has no predators in the UK.
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 of northwestern Europe, and arrived in Britain in summer 2004.
It has spread rapidly throughout the southeast of England since its first sighting.
There are 46 species of ladybird (Coccinellidae) resident in Britain and the recent arrival of the harlequin ladybird has the potential to jeopardise many of these. The Harlequin Ladybird Survey will monitor its spread across Britain and assess its impact on native ladybirds.
http://www.harlequin-survey.org/
Attack of the Killer Ladybird
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