THE most invasive ladybird on earth has made its home in Canterbury and experts fear it could wipe out the native British ladybird and other insects including some butterflies.

A Cambridge professor warned on a national news programme that the Harmonia axyridis, known as the Harlequin ladybird, was spotted for the first time in this country in a garden in Essex on September 19.

The following day Caroline Ponsonby, 11, spotted a Harlequin at a pond belonging to her school, Canterbury's Barton Court. Cambridge genetics expert Dr Michael Majerus identified it as the ladybird in question.

Caroline later found two more of the beetles, which have proved deadly and aggressive predators of indigenous insects in Asia and North America where it used as a pest control.

Dr Majerus is now urging anyone who spots a Harlequin ladybird to send it to him with precise details of where and when it was found.

"This is without doubt the ladybird I have least wanted to see here," said Dr Majerus, who admits to having a fondness for the beetles. "Now many of our ladybirds will be in direct competition with this aggressively invasive species and some simply will not cope."

Introduced from Asia into North America for the control of aphids, it has swept across the United States, becoming by far the commonest ladybird in less than a quarter of a century.

In America the Harlequin has also come into conflict with humans as some houses are inundated with thousands of the beetles seeking places to pass the winter.

"It is critical to monitor this ladybird now before it gets out of control and starts to annihilate our own British ladybirds," said Dr Majerus.

Anyone who spots a Harlequin should contact Dr Majerus at the Department of Genetics, University of Cambridge, CB2 3EH or on 01223 356372.