Friday, 3 July 2009

Plauge of the aphids

The sizzling temperatures and scorching sunshine has triggered the worst plague of greenfly for more than 25 years in the UK.

Experts say the blazing June weather has provided perfect breeding conditions for aphids - the tiny pests hated by gardeners that destroy everything from cannas to cabbages.

Billions of the green, black and white pests have been spotted swarming in the skies and munching through flower beds in recent weeks.

'It is the perfect conditions for greenfly,' said John Hughes, an expert from Shropshire Wildlife Trust.

'We've had a warm, wet spring going into early summer and things have been growing very well, so everything that lives on plants, like greenfly, is doing very well.'

The sap-eating bugs are a threat to a quarter of all common garden plant species.

The insects are usually between 1mm and 6mm and are usually known as greenfly or blackfly. However, they come in a range of colours including pink, white and mottled.

Aphids infest the softest parts of the plant, usually the tips of shoots and the undersides of young leaves and suck out the sweet sap.

They spread diseases from plant to plant, restrict growth and can cause deformities in leaves and stems.

Greenfly also secrete a sugar solution which creates sticky patches on plants and is often colonised by a fungus called sooty mould that turns foliage black. Although this does not directly damage plants it can block out light to the leaves and reduce the plant's ability to photosynthesize.

Worst of all, they are distributors of Canna virus, moving from an affected plant onto an unaffected plant and contaminating that. Although we always try to be as organic as possible, however the size of the problem has meant that we have sprayed all the Cannas in the colection with a systemic bug killer, and we will top that up again weekly.

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