Aphid Control and Treatment
There are many species of aphids but almost all respond to the same
control and treatments. A large variety of chemical sprays are available from your
garden centre to treat aphids, but all will have some bad affect
on other beneficial insects and wildlife.
Where edible crops are sprayed
with these chemicals, some of the chemical will also remain
within the flesh of the plant.
A better line of attack is to encourage other insects which feed
on aphids. Research has very
positively shown that planting certain plants (e.g. tagetes, calendula,
poached egg plant, morning glory)
near the plants which are often attacked by aphids results in much lower
numbers. The aphid's enemies include hoverflies, ladybirds,
lacewings and birds.
The important point to consider with attracting
beneficial insects is that those insects rely on a steady source
of aphids. When the aphid population drops below a certain
level, the insects will go elsewhere. This in turn will allow
the aphids to multiply. The solution to this problem is the
There are a couple of reasons why nettles are so
good for protecting your plants. Firstly, they will attract the
nettle aphid which is a good source of food for lots of aphid
eating insects. Nettle aphids are also one of the earliest to
appear in the year which is good news for the ladybird. Nettle
aphids won't attack your other plants because they only feed on
nettles. So, not all aphids are bad news!
The picture on the right is of aphids
colonising a plant and causing typical damage. The leaves
curl inward effectively protecting the aphids from
They tend to attack tender young shoots, emerging
leaves and twigs.
The commonest varieties are whitefly and greenfly. As
well as causing damage on their own behalf they encourage
other pests and diseases.
The reason some flowering plants help prevent
aphids is clear, the plants are the feeding favourite of the
hoverfly. Hoverflies have short feeding tubes and they prefer
have flat and open flowers. This helps the hoverfly to easily
reach the pollen. After feeding, the adult hoverfly will then
lay her eggs on colonies of greenfly and black fly. When the eggs hatch, the
resulting larvae feed on the aphids with dramatic effect! Try it, it really does work.
friendly ways of controlling aphids include rubbing them off with your fingers, spray them off with water and the use of
insecticidal soap (a potassium-salt soap available at most
garden centres). Many people have success by spraying weekly
with very diluted washing up liquid - about one teaspoon of
Fairy Liquid to a couple of litres of water.
Aphids breathe through their skin. Spraying with
diluted washing up liquid clogs up their skin and causes them to
literally suffocate. Their brains are unable to detect pain
according to the majority of research, so don't worry unduly
about any pain this may cause!