Emily Beament, The Independent 1 Jul 09;
The recent arrival of the invasive harlequin ladybird in the UK is likely to threaten more than 1,000 native species, scientists warned today.
The harlequin has become a common sight as it has spread across the country in the past few years - even invading houses in the autumn to hibernate over winter in warm spots.
The ladybird is originally from Asia but was introduced in continental Europe to control pest insects which were damaging crops and has since spread to the UK on fruit and flowers and by being blown across the Channel.
A survey launched in 2005 has, with the help of the public, managed to track its progress using some 30,000 online records.
Since its arrival in 2004, the ladybird has spread from Essex to Orkney in just four years, with places such as London parks now recording staggering numbers of the insect.
The bug is a "voracious" predator, which preys on a wide variety of insects, including the larvae of other ladybirds, caterpillars and even fruit, and out-competes with native species.
As a result, the species poses a major concern for the UK's wildlife according to Dr Helen Roy of the Centre for Ecology and Hydrology (CEH).
Evidence from the US, which introduced the harlequin more than 20 years ago, shows "severe declines" in native species.
"We believe that the negative impacts of the harlequin on Britain will be far reaching and disruptive, with the potential to affect over 1,000 of our native species," she said.
"It's a big and voracious predator, it will eat lots of different insects, soft fruit and all kinds of things. Its reproductive capacity is also immense."
The harlequin ladybird has a variable appearance, is very difficult to tell apart from our native ladybirds, and can chomp through more than 12,000 aphids a year.
But it is also known to eat species such as lacewing larvae as well as pest insects carrying pathogens, depleting the supplies of the diseases which normally keep such species under control.
It will try anything it comes across when hungry, and had even been recorded eating the caterpillar of a brimstone butterfly, Dr Roy said.
Scientists from five organisations are presenting information about the harlequin at the Royal Society Summer Exhibition this week, and warn its arrival will mean "one winner, 1,000 losers".
Ladybirds do not have many enemies, as they are distasteful and toxic to many predators and let would-be diners know this with their bright colouring.
The harlequin ladybird has even fewer predators as it is not a native species.
But the researchers are exploring how the few native enemies that exist, including fungal disease, male-killing bacteria, parasitic wasps and flies, could be used to control the population - or may evolve to tackle the harlequin naturally.
One of the most promising ideas could involve encouraging the transmission of a sexually transmitted mite which makes some ladybirds infertile in a bid to reduce the harlequin population.
Dr Remy Ware, of the University of Cambridge, who is working on how the mite could control harlequin populations, said it was a naturally-occurring UK species which did not affect most British ladybirds because of their breeding cycles.
She said her team was examining if it could be artificially transferred to harlequins, where the ladybird's breeding pattern may allow it to be naturally transmitted, causing females to become sterile.
Dr Roy also said that if the harlequin is found in the habitat of rare ladybirds such as the five spot, which lives in just a few sites of disturbed river shingle in Wales, it may have to be physically removed to protect the native insect.
But she warned: "We haven't got a hope of blanket control of the harlequin ladybird. Anything we do here we'd have to do in other countries in Europe."
And she said the researchers were not encouraging people to kill harlequins as it would make no difference to the overall population and they may accidentally kill native species.
The scientists from CEH, the University of Cambridge, Anglia Ruskin University, Rothamsted Research and the University of Hull, will be at the Royal Society's Summer Science Exhibition this week.
They will be explaining how to tell the difference between harlequins and native species and what methods might be used to control the invasive insects.
* The Royal Society's Summer Science Exhibition is free to the public. It runs from Tuesday June 30 to Saturday July 4 at the Royal Society, 6-9 Carlton House Terrace, London.
Invading ladybirds breed up ecological storm for UK species
A voracious predator, the Asian harlequin ladybird has spread across the UK since its arrival from continental Europe in 2004
David Adam, guardian.co.uk 30 Jun 09;
Millions of very hungry ladybirds are poised to create ecological havoc for hundreds of Britain's native species, scientists warn today.
Experts said the anticipated warm summer would provide the 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.
The insect, a voracious predator, has spread across the UK since its arrival from continental Europe in 2004. The bugs have been spotted as far north as Orkney, though they remain strongest in south-east England, where they have overrun many of London's 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," she 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 for adults to reach sexual maturity, and so be able to breed. "That gives them a massive advantage," Roy said.
The ladybird, originally from Asia, was introduced to Holland and other European countries to control aphids on crops. From there, it crossed the English Channel on the wind, or hidden on fruit and flowers.
A public survey launched in 2005 has tracked its progress using some 30,000 online records. 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, as well as feed on other species such as lacewing larvae. The harlequin has even been recorded eating the large caterpillar of a brimstone butterfly.
Scientists from five organisations will present the latest findings on the spread of the harlequin this week at the Royal Society summer exhibition, and warn its arrival will mean "one winner, 1,000 losers".
Scientists are exploring whether harlequin numbers could be controlled using their few native enemies, such as fungal disease, male-killing bacteria and parasitic wasps and flies. One idea is to encourage the transmission of a sexually transmitted mite that makes some ladybirds infertile.
The researchers said people should not take matters into their own hands. Vigilante action against the harlequin invaders would make no difference to the overall population and could inadvertently kill similar-looking native species.
Ladybird 'risk to 1,000 species'
BBC News 30 Jun 09;
The Harlequin ladybird is putting over 1,000 species in the UK in peril, scientists have warned.
"The rate of spread is dramatic and unprecedented," said Dr Helen Roy of the Centre for Ecology and Hydrology.
The ladybird has spread to most parts of the UK in just four years, preying on many other insects.
However, research outlined at the Royal Society's Summer Science Exhibition suggests local ladybird parasites are adapting to prey on the interloper.
To help that process along, scientists are suggesting introducing a mite that renders the ladybirds infertile.
Originally from Asia, the harlequin preys on a wide variety of insects, including the larvae of other ladybirds, and will also eat fruit.
It was introduced in continental Europe to control pest insects.
First "spotted" in Essex in 2004, the invader was quickly classified as a major threat to the UK's 45 native ladybird species.
Since 2005, its spread has been tracked by a survey inviting members of the public to report sightings.
'Top predator'
"What we've seen is that the southeast is the stronghold, but they have also reached Orkney, Northern Ireland, far west Wales and far west Cornwall," said Dr Roy.
The researchers have also worked out how the insect fits into the UK's ecology.
"The Harlequin ladybird is a top predator and we know that it sits within a web of many other insects that it interacts with, and other organisms as well," Dr Roy told BBC News.
"Because there's nothing very much that attacks it, we believe that 1,000 species all have the potential to be impacted."
Dr Remy Ware of Cambridge University is looking into potential measures to stop the frantic spread of the ladybirds.
She said that some natural enemies of UK ladybirds, known as parasitoids, are adapting to prey also on the Harlequin. Parasitoid flies and wasps lay their eggs inside ladybirds, killing them.
"We have evidence from the past two years that these two groups may be adapting to attack harlequin as a novel host," Dr Ware told BBC News.
Mite work
Another more promising predator for the insects is a sexually transmitted mite that renders female ladybirds infertile. The mite must be passed from one generation to the next by inter-generational mating.
Native ladybird species produce just one generation per year, which does not leave enough time for the mite to propagate.
But the Harlequin has as many as five generations per year, making it an ideal candidate to carry and pass on the mite.
"We're not suggesting that we would introduce a novel enemy into the UK; it's actually already here and in time we expect it would naturally take on in the harlequin," Dr Ware said.
"We've developed methods whereby we can artificially infect Harlequin ladybirds with the mite - it'd be a case of infecting them and releasing into the wild."
However, Dr Ware stresses that the suggestions are still in the formative stages.
