Foreign insects are to be released into the UK to tackle a thriving Far Eastern weed blighting Lincolnshire's countryside.

The jumping plant lice, which measure just 2mm long, will be released to tackle the aggressive Japanese knotweed plant, which has been seen sprouting up in many county parks, gardens and riverbanks.

Government officials announced that a species of psyllid lice will be released into the countryside to battle the spread of the highly aggressive weed, as it does in its native Japan.

Japanese Knotweed was introduced as a decorative plant in gardens in the early 19th Century but has spread into the countryside, where it can grow up to a metre a month.

It currently has no natural enemies in Britain and can cause damage to buildings, roads and railways and can overcrowd native wildlife.

City building firm Delta Simons, based in Union Road, Lincoln, has had problems with the weed and previously had to call in specialist removal teams before they could start work.

Project director Alex Ferguson said: "I have known cases where knotweed has knocked over walls.

"I don't know whether the insect will eradicate the problem completely but it will help in areas such as riversides and near to railway lines."

Rachel Shaw from the Lincolnshire Wildlife Trust said: "Introducing any non-native species for biological control carries risks and we must be cautious as the impact is difficult to predict.

"We are fortunate that it does not occur on the vast majority of our nature reserves."

The lice will be released into two undisclosed UK sites and monitored over the next few months before being rolled out across other sites in the country.