Hunt on for 'deadly ladybird'

The invader (r) is usually very different in colour and pattern to native UK bugs

A 'deadly' ladybird which has already caused havoc to native insects in America could be on its way to Northern Ireland.

Harmonia axyridis could threaten butterflies, lacewings and many other ladybirds.

However, insect expert Dr Keith Day dismissed stories of a voracious bug that bites people.

The new ladybird is an Asian species which was introduced into North America 25 years ago to fight aphids.

It has spread to Europe and last month was discovered in a pub garden in Sidle Hedingham, Essex.

Dr Michael Majerus of Cambridge University said the ladybird, which is also known as harlequin or the multi-coloured ladybug was "without doubt the ladybird I have least wanted to see here.

"I knew it was on its way, but I hoped that it wouldn't be so soon. Now many of our ladybirds will be in direct competition with this aggressively invasive species, and some will simply not cope."

Harlequin ladybirds can damage soft fruit crops

However, Dr Day from the School of Environmental Studies at the University of Ulster, Coleraine, told BBC News Online that horticulturalists and gardeners in Northern Ireland should not panic... just yet.

"As far as we know, it has not reached Northern Ireland," Dr Day said.

He said there was always a potential for this ladybird to spread quite naturally. But it had never flown over to Northern Ireland.

The ladybird has been introduced in Holland as a biological control to get rid of sap sucking pests like aphids. This had also happened in the United States.

"Most people are against greenfly. If this is a species that is more effective, gardeners and horticulturalists will be generally pleased," Dr Day said.

And he added that he was reluctant to accept it would prove a "terrible nuisance", biting people and swarming in their houses, whilst releasing an oily, foul smelling yellow blood when stressed.

"All ladybirds nip, but they do not generally get a grip on your skin," Dr Day said.

"When they swarm, they move to higher ground. They release chemicals as a protection against predators. They can be a bit of a nuisance,"

However, he added that this was not of major concern, as long as the existing species was not depleted completely,

The adult H. axyridis is about 7mm long, slightly larger than the seven-spot ladybird native to the UK. It comes in a range of colours and patterns.

The one found in Essex was black with two very bold red spots and two smaller red spots. But the bugs can also be orange in colour and checked in pattern.

H. axyridis is still sold in North America as a pest control.

Time to defend

The harlequin ladybirds are also still being sold in continental Europe by biocontrol companies. The bug now roams across France, Belgium and Holland, with numbers soaring annually.

Harlequins also feed on fruit juices as they fuel up for the winter and fruit-growers are finding that they blemish many soft fruits, reducing the value of the crop.

Wineries report the bugs also taint the vintage because of their acrid defensive chemicals.

Dr Day said that anyone who finds the insect should send it to him with details of where and when it was found.

The address is Dr Keith Day, School of Environmental Sciences, University of Ulster, Coleraine.