British ladybugs are in danger of being overrun by insects from Central and Southeast Asia that are encroaching on their food supply, experts said Wednesday.
Harlequin ladybugs, already a pest in North America, were first spotted in Britain in September 2004 and are flourishing without the presence of natural predators.
Michael Majerus, of Cambridge University, predicted the foreign ladybugs — the insects are known in Britain as ladybirds — could be found all around the country by 2008.
"There are currently 46 species of British ladybird," he said. "A few of those may be lost 10 to 20 years down the road."
Scientists launched a survey at the Natural History Museum in March to track the pesky beauties. Majerus said the public had been extremely helpful.
Harlequins are orange with black spots or black with either red or orange spots and larger than their British counterparts.
Introduced to the United States to control aphid populations, the harlequins morphed into pests by 1988, blemishing soft fruit, ruining grapes meant for wine production and invading homes.
After similar insect control programs in continental Europe, harlequins made their way to Britain by hitching rides on flowers shipped from the Netherlands and Belgium.
The bugs are able to fly for miles and up to 10,000 feet high and Majerus believes that many simply flew over the English Channel.
Harlequins have a voracious appetite and eat aphids, pollen, nectar and even other ladybugs. They have even been known to nip humans when hungry.
If temperatures are right, harlequins can produce two or three generations annually. Native British ladybugs are limited to one generation per year.
Harlequins also threaten other species that eat aphids, and those who, in turn, eat them, and can disrupt entire ecosystems.
"This is a concern worldwide in terms of invasive species unless we want to have a global fauna," said Helen Roy, a ladybug expert at Anglia Polytechnic University.
Currently, scientists have no way of stopping the bugs.