The Harlequin Ladybird (Harmonia axyridis), otherwise known as the Multi-Coloured Ladybird or the Halloween Ladybird, was introduced to North America from Asia in 1988, originally for their aphid-eating abilities. It took several attempts to establish a colony there, so this was not accidental, but a deliberate, planned event by the United States Dept of Agriculture that was to have global implications.

This ladybird is now the most common variety found in the whole of the United States.

At a later date the harlequin was introduced to Holland, primarily for aphid control on crops, and from there it migrated across the English Channel and was first spotted in southern England in 2004.

Since then it has spread both north and east, and is now reckoned to be the biggest ecological threat since the introduction of the grey squirrel, another creature without natural predators, which all but wiped out the red squirrel population

Bigger than any of the 34 indigenous species native to the the British shores, the Harlequin as it is known in Britain because of its varied colours, not only eats voraciously the same food destined for the British ladybirds, it also eats the smaller native ladybirds and their eggs, as well as the eggs and larvae of many other insects, some beneficial and others less so.

Scientists believe that up to 100 species are now at risk because of this incomer, dubbed the most invasive ladybird in the world.

It is also cannibalistic. It will eat other harlequin ladybirds as well as their own eggs if they are hungry. This happens when the aphid and native ladybird populations die down, as is natural at certain times of the year.

They are also attracted to anything sweet, like fruit, and have been responsible for ruining wine harvests by altering the taste of the grapes with their excretions.