UK may bring in insect to tackle Japanese Knotweed

LONDON (Reuters) - Britain is considering the introduction of a tiny plant-eating insect to tackle the spread of Japanese knotweed in the first such use of a biological controlin Europe, officials said on Thursday.

The government has launched a public consultation on whether to grant a licence to introduce the Aphalara itadori psyllid which naturally controls the invasive weed in its homeland in Japan.

The knotweed, which can grow more than a metre a month and was brought to Britain in the 19th century as an ornamental garden plant, is considered one of the most damaging invasive weeds in Europe and North America.

It can have a devastating effect on indigenous species and is also capable of pushing through tarmac and concrete, costing millions of pounds worth of damage to roads, buildings and railway lines.

Government officials estimated in 2003 it would cost more than 1.5 billion pounds to eradicate it from Britain using conventional methods.

Scientists at CABI, a not-for-profit research body, have spent five years trying to find the best natural control and concluded the psyllid was the best option.

“It’s the only long-term solution we can see -- we can’t continue what we’re doing, and doing nothing is not an option,” Dr Dick Shaw, Principal Investigator at CABI, told BBC Radio.

If granted a licence, Britain said it would be the first time a non-native insect had been used in Europe to control a plant species.

Other attempts at biocontrol have had terrible environmental impacts, most notably the decision to introduce cane toads to Australia to control cane beetles. Just over 100 were brought from Hawaii but now there are more than 200 million.

However, the Department for Environment, Food and Rural Affairs said tests had been carried out on about 90 other plant types which indicated the insect would not survive on any closely related species.

Shaw said CABI did not have any doubts over whether it was safe to introduce the insects but he warned it could take some years to see they would be effective.

“One of the problems we have with biological control is we can never predict success,” he said.

“We can predict safety and what it won’t do and you are often pleasantly surprised and horribly disappointed. But this one is showing all the characteristics of something that should be able to reproduce, spread and damage the plant.”

Editing by Steve Addison