|
A deadly species of ladybird with the potential to
wipe out half of Britain's native species has arrived in the
country.
The voracious Harlequin, also known as the
multi-coloured Asian ladybird, was discovered in a pub garden two
weeks ago.
| |
![]() |
|
The common ladybird is in danger from the vicious
Harlequin |
The insects are larger, hungrier and more adaptable
than their domestic rivals. If they become established, they could
drive traditional species, such as the seven spot or two spot, to
extinction within decades, scientists say.
Dr Michael Majerus, a ladybird specialist from
Cambridge University's genetics department who identified the
"odd-looking" Harlequin, said: "This is the ladybird I have least
wanted to see here. Given its proximity in Holland, I knew it was on
its way. But I hoped that it wouldn't be soon.
"Now many of our ladybirds will be in direct
competition with this aggressively invasive species. Some will not
cope."
Harlequin ladybirds, Harmonia axyridis, originated
in Asia. They were introduced to North America in the 1970s as an
"environmentally friendly" alternative to pesticides and quickly
swept across the continent, driving out domestic species and other
aphid-eating bugs. Numbers of the insects are also rising steeply in
France, Belgium and the Netherlands.
Harlequins are more adaptable than most species,
living in trees as well as the ground. In the spring, they
out-compete rivals for aphids. Once aphid numbers start to fall in
the summer, they turn their attention to hoverflies, lace wings,
butterfly eggs and even other ladybirds.
The species is a threat not only to other ladybirds:
in America in the autumn, some houses are inundated with swarms of
harlequins seeking warmth for the winter.
When stressed, they release oily, foul-smelling
yellow blood from their legs which stains carpets and fabrics, and
may trigger allergic reactions. Reports of harlequins biting people
as they run out of aphid prey have risen, Dr Majerus said. They also
damage soft fruit.
Two weeks ago, Dr Majerus's colleague Ian Wright
spotted an "odd" ladybird in the garden of the White Lion in Sible
Hedingham, Essex. Dr Majerus identified it as a harlequin.
"As far as we know, this is the first to be reported
in Britain," he said. "If it becomes established, I could well
imagine we could lose half of our 40 species of ladybird." There are
around 40 species of ladybird in Britain ranging from the common
seven spot and two spot to the more unusual and specialist pine and
orange ladybirds.
Ladybirds can travel long distances on the wind. The
Essex harlequin is likely to have been blown across the Channel. Dr
Majerus called on anyone who finds an unusual ladybird to post it in
a sealed matchbox or film canister to his laboratory at Cambridge
with details of where and when it was found.
"It is critical to monitor this ladybird before it
starts to annihilate our own British ladybirds," he said. Harlequins
vary in colour and pattern. Some have black spots on orange wing
covers, others have big orange or red spots on black wing
covers.
They are around 6mm to 8mm long. Most also have a
distinctive W or M mark on the area separating their heads from
their wing covers.
Send them, in clean, dry containers, to: Dr Michael
Majerus, Department of Genetics, Cambridge University, CB2
3EH. | 
