MILLIONS OF very hungry ladybirds are poised to create ecological havoc for hundreds of Britain’s native species, scientists warned yesterday.
Experts said the anticipated warm summer would provide perfect conditions for the Asian harlequin ladybird to breed and prepare for a springtime assault.
“They are creating a huge genetic stock ready for next year,” said Helen Roy, a scientist with the Centre for Ecology and Hydrology in Oxford.
The insect, a voracious predator, has spread across the UK since its arrival from continental Europe in 2004. They have been spotted as far north as Orkney but remain strongest in the southeast, where they have overrun many London parks.
“We believe that the negative impacts of the harlequin on Britain will be far-reaching and disruptive, with the potential to affect over a thousand of our native species,” Ms Roy said. “It’s a big and voracious predator. It will eat lots of different insects, soft fruit and all kinds of things.”
Unlike British ladybirds, such as the most common seven spot, the harlequin does not need a cold winter to reach sexual maturity and be able to breed.
“That gives them a massive advantage,” Ms Roy said.
The ladybird, originally from Asia, was introduced to the Netherlands and other European countries to control aphids on crops.
It then crossed the English Channel in the wind or hidden on fruit and flowers.
A survey launched in 2005 has tracked its progress using some 30,000 online records. Ms Roy said the results revealed a “staggering expansion”. Scientists fear the harlequins will push out natural rivals through competition for food. They can munch through more than 12,000 aphids a year and eat other species. The harlequin has even been recorded eating a large caterpillar.
Scientists from five organisations will present the latest findings at the Royal Society summer exhibition, warning its arrival will mean “one winner, 1,000 losers”.
They are exploring whether harlequin numbers could be controlled using their few native enemies, such as parasitic wasps and flies. However, the researchers said people should not take matters into their own hands: vigilante action would make no difference to the overall population and could inadvertently kill similar-looking native species.
The director of the Irish National Biodiversity Data Centre, Liam Lysaght, said the harlequin had not been found in the wild in Ireland, but it was one of a number of invasive species the centre was tracking.