Aphids are soft skinned sap-sucking insects. They are tiny animals about 2 to 8 mm long. Aphids come in a range of colours: green, black and brown, whitish and light red. Other names are black-fly and green-fly.

Most aphids species specialise on particular host plants. They are a serious and if not contained devastating pest. Aphids proliferate quickly because they can reproduce non-sexually.

Most aphids don’t move easily on their own. They can travel wide distances with the wind, very few species develop wings if the place they occupy gets too crowded.

Aphids usually live in a symbiotic relationship with ants. The ants protect the aphids against predators and carry them to new ‘grazing grounds’. The aphids supply the ants with a sweet honeydew that they excrete.

Aphids are a concern because they:

  • suck plant sap, which weakens the plant and leads to yellow, mottled, curled and wilted leaves and plant death
  • they transmit plant viruses
  • excrete a sweet honeydew that sticks to the plants and is a perfect breading ground for fungi like sooty mould

Predatory wasps and the larvae of lacewings, ladybirds, hoverflies, and some blues (butterflies) prey on aphids.