Aphids

Generally 1-5mm long with a soft body, long legs and antennae, and usually a prominent pair of tube-like structures at the end of the abdomen. Aphids come in a selection of colours, with more than 500 species in Europe. They exist in both winged and wingless forms.

There are over 4,000 types of Aphid, of which 250 are known as pests to our garden plants and food crops.

In large numbers clustered around tender young growth they cause young shoots to become weak and distorted, sometimes killing the plant. Aphids consume large volumes of sap, excess being secreted as a sticky ‘honeydew’ that may coat the leaves beneath. Sooty moulds may develop on the honeydew-coated leaves.

Some ants ‘farm’ aphids for the honeydew that they produce. This means that they protect them from predators and move the pests around a plant to new ‘pastures’. If a tree is badly infested with ants and aphids, a band of insect glue round the trunk stops the ants climbing up the tree. Without protection, aphid numbers will decline as they are exposed to more parasites and predators.

Avoid using too much nitrogen-rich fertiliser which encourages soft leafy growth which is attractive to aphids. 

Encourage creatures that feed on aphids, such as birds, insects and their larvae, earwigs and bats. 

Grow flowers that attract hoverflies, lacewings and ladybirds (see How to grow flowers to attract beneficial insects). 

During winter, hang up pieces of fat in fruit trees and above rose bushes to attract blue tits which eat aphid eggs. 

Inspect plants regularly and squash any aphids that are seen. Pick off heavily infested shoots and leaves and drop into a bucket of soapy water. A strong jet of water can also dislodge them.

Covers such as horticultural fleece can give good protection against aphids and the viruses they transmit.