Tuesday 17 May 2011

Insect Invaders From Asia and Europe


They may be pretty to look at, but these colourful bugs are attacking garden plants across Britain.
An army of exotic invaders is devouring leaves and stripping stems bare up and down the country.
Lilies and popular herbs such as rosemary and sage are falling prey to the alien bugs from Europe and Asia.
Illegal alien: Bugs from Europe and Asia are attacking garden plants up and down Britain
Illegal alien: Bugs from Europe and Asia are attacking garden plants up and down Britain
Scarlet lily beetle: The insects used to be found only in southern England but have recently been spreading into other parts of Britain
Scarlet lily beetle: The insects used to be found only in southern England but have recently been spreading into other parts of Britain

THE INVADERS

Rosemary beetle (Latin name: Chrysolina americana)
These have bright green metallic wing casings with purple stripes and are about 8mm long. They feed on the leaves of rosemary, lavender, thyme, sage and other related plants and are active in summer months and warm winter days.

Scarlet lily beetle
 (Latin name: Lilioceris lilii)
Bright red or scarlet with a black head and legs, also about 8mm. Eats leaves, stems, buds and flowers of lilies and fritillaries between April and September.

Berberis sawfly
 (Latin name: Arge berberidis)
Blue/black flies with dark grey wings and upswept antennae with white caterpillar-like larvae which eat the leaves of Berberis and Mahonia plants between May and October.

Hemerocallis gall midge
 (Latin name: Contarinia quinquenotata)
Tiny fly that lays its eggs inside lily flowers in May through to July; small white maggots develop leaving the buds swollen and unopened.
The insects, which have been infiltrating our flowerbeds and taking their fill of our foliage, include the brightly-coloured rosemary beetle, the scarlet lily beetle, berberis sawfly and the hemerocallis gall midge.
They used to be found only in southern England but have recently been spreading into other parts of Britain, even as far north as Scotland.
Scientists are blaming climate change and the import of plants from abroad for the spread of the foreign pests and are warning gardeners to look out for the destructive insects.
Andrew Halstead, principal entomologist at the Royal Horticultural Society, said: 'It is quite worrying how widespread they now are.
'They defoliate the plants or spoil the flowers. Even it they do not kill the plants, they leave them weakened.
'The main reason for their continued arrival in Britain seems to be from imported plants. Climate change is almost certainly playing a role in their spread.
'As the summers have got warmer and winters milder, it has allowed pests that were restricted to the south of England to spread further north'
The Environment Agency said it is fighting a losing battle against the plant-eating bugs, which could threaten food-producing plants and trees as well as just garden shrubs and flowers.
Berberis sawfly: Scientists are blaming climate change and the import of plants from abroad for the spread of the foreign pests
Berberis sawfly: Scientists are blaming climate change and the import of plants from abroad for the spread of the foreign pests
Hemerocallis gall midge: Lilies and popular herbs such as rosemary and sage are falling prey to the alien bugs
Hemerocallis gall midge: Lilies and popular herbs such as rosemary and sage are falling prey to the alien bugs


Link: http://www.dailymail.co.uk/sciencetech/article-1348287/Insect-invaders-The-alien-bugs-eating-way-British-landscape.html#ixzz1MkGv5qUj