Asian Bug Threatens British Plant

[ed. Oh the Irony!]

Source: Daily Mail
By David Derbyshire
14th May 2009

Invading Asian bug could wipe out swathes of Britain's wisteria plants.

Its stunning displays of lavender and violet flowers are a welcome sign of the arrival of summer.

But Britain’s wisteria plants are under threat from a bug that is spreading across the country.

The wisteria scale pest was first found in the UK eight years ago, having been introduced on imported plants.

Under threat: The wisteria scale bug could destroy the beautiful crops found on cottages and historic properties across the country like the 100-year-old variety found on this home in Dorset

It was discovered in the South-East, but experts warn it is spreading into the North and West.

The shell-like wisteria scale can be up to 1cm long – bigger than other species of scale – with a distinctive brown lumpy body.

They damage the plants by sucking sap from leaves and stems. The bugs cannot fly but spread from plant to plant by becoming attached to birds’ feet and feathers.

The Royal Horticultural Society fears the bug has the potential to wipe out swathes of wisteria and is warning gardeners to watch out for infestations.

Andrew Salisbury, of the RHS, said: ‘Our records show it is spreading slowly but like all things it could suddenly mushroom.

'Heady infestations could cause die-back in wisteria so gardeners should definitely keep an eye out for it.’

Changes in weather and the increased global movement of plants are thought to be to blame for the influx of wisteria scale and other pests, such as the scarlet lily beetle, berberis sawfly and rosemary beetle.

Killer bug: The wisteria scale insect attaches itself to the plant and grows a grey sack full of thousands of eggs before they hatch and crawl up the plant to feed

This particular species of scale was originally found in Asia where it attacks fruit trees.

In Britain, however, it appears to be mostly confined to wisteria, which flower for around four weeks in May and June.

Andy Strachan, of Garden Organic, said: ‘They are like little shells and when they breed they erupt and turn fluffy and let out tens of thousands of little scales which then walk about the plant.

‘They are transferred from one plant to another by birds.

‘When the new nymphs settle on the next plant they pierce the stem and suck out the sap. It’s awful. Wisteria are stunning plants and this can really ruin them.’

So far the scale has been found only in London and the South-East on isolated plants but there is evidence that it is spreading – worrying news for many National Trust and other historic properties famed for their beautiful wisteria.

Mr Salisbury added: ‘We have already had reports of sightings this year. The scale does appear to be established and spreading slowly.

‘If anyone spots it they should get it diagnosed properly.’