Aphid~
Distorted leaves
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Sticky sooty leaves
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Black aphid colony
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Green aphid
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Black Aphid
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Yellow Aphid
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Description
The most common of all pests and almost every plant from the smallest shrub to the tallest oak tree can be infested at one time or another.
Visual Symptoms
The little ‘bugs’ feed on the sap of the plant weakening it and reducing its rate of growth. They can also transmit a virus to the plant.
Plant leaves will invariably become curled or distorted.
The aphid colonies gather on the undersides of the leaves as they suck the sap, so they excrete a sugary honeydew on the leaves below – developing a shiny glaze.
Particularly in damp conditions, a sooty mould will grow on the honeydew glaze which is not unsightly but will gradually deprive the leaf of the light and indeed the plant with the wherewithal to survive.
Aphids also shed their skins as they increase in size. Cast off skins gather on the leaf surfaces below forming a whitish dust.
Treatment and Control
There are a number of options from which you can choose.
Spray with a natural-based insecticide - Pyrethrum (a natural plant extract) base insecticides will control aphides and other plant pests. An example is:
- NATURE’S ANSWER® TO INSECT PESTS
For best results spray thoroughly as pyrethrum kills on contact. Alternatively infected plants can be treated with Derris Dust or Insecticidal Soaps.
Spray with selective organic insecticide - Rape Seed Oil based insecticides will specifically kill aphids but will not affect other pests and they will allow beneficial insects (ladybirds, lacewings and bees) to flourish. An example is:
- Bio, organic pest control.
Spray with general insecticide - most broad spectrum insecticides will control aphids. Examples are:
- BUG CLEAR GUN!® FOR GARDENS (contains bifenthrin)
- SYBOL® EXTRA (contains bifenthrin)
They kill very quickly on contact, and also have a residual effect which lasts for a few days.
To prevent infestation - if plants are container or pot grown protection can be achieved by using compost containing an active ingredient called imidacloprid. This will prevent infestation for up to twelve months. An example is:
- LEVINGTON® PLANT PROTECTION COMPOST WITH INTERCEPT
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