Lice to attack Japanese Knotweed
An ornamental plant introduced by gardeners centuries ago, Japanese Knotweed has become a pest across the country pushing out native species and costing thousands of pounds in clear-up efforts. The Government has now given the go-ahead to the introduction of a species of lice known as a psyllid from Japan, the larvae of which then suck the sap and kill the plant within weeks.
Following tests on other plant species, Defra the Department for Environment, Food and Rural Affairs, insist the introduced psyllid will not cause problems of its own to native plants but will be an effective control to Japanes Knotweed.
The introduction of the insect will be the first form of bio-control used in the UK, though other countries have used this method to control problematic species with mixed results. In Australia, the introduction of the cane toad to control the cane beetle resulted in the loss of other species, but diseases introduced to control the European rabbit population have been successful in controlling numbers.
Huw Irranca-Davies, Wildlife Minister, said the “ground-breaking” project offers real hope against this plant which takes over areas of ground to the exclusion of other plant life. “These tiny insects, which naturally prey on Japanese Knotweed, will help free local authorities and industry from the huge cost of treating and killing this devastating plant,” he said.
The lice will be released into three secret sites over the next few months and closely monitored before other sites are chosen. Sophie Thomas, invasive plants officer at Plantlife, welcomed the move as long as the introduction is closely monitored for its effect on other plants and invertebrates.
“Plantlife believes that concerted and systematic effort has gone in to selecting the control agent that is least likely to cause damage beyond the intended target species or itself become invasive. However, bio-control will never be a risk-free process and all possible outcomes cannot be predicted nor mitigated against.” To find out how you can help in preventing other invasive species becoming problematic, in particular aquatic species like floating pennywort and water fern, visit the Plant Wise site.
