Plant aphids, Plant lice
One of the most common garden pests, aphids are small sap-sucking insects that are often seen feeding in clusters on new plant growth. There are over 4000 species worldwide and in low to moderate numbers, they are generally not too harmful to plants. However, a general decline in plant vigour will be noticed with a substantial infestation. Aphids feed on the cell contents of plant leaves, which over time reduces the green leaf area available for photosynthesis.
Aphids produce large amounts of honeydew. This sticky fluid drips on plants and attracts ants and can also promote sooty mold growth on leaves.
Aphids are a source of food for especially ladybugs and lacewings.
Aphids may be green, brown, yellow, black or red in colour depending on species and their food source. They are rather small and have pear-shaped bodies that are soft. Some may have a waxy or woolly coating and are known as 'Woolly aphids'.
- Colonies of aphids clustered on young stems, leaves and buds - Wilting and distortion of leaves and young shoots - Yellowing and premature death of leaves and young plants - A sticky substance on the plant or leaves, known as honeydew
Natural predators include ladybirds, wasps and lacewings. Aphids can also be treated with a strong jet of water to dislodge them from the plant or a light, soapy mixture applied to the plant or even just squashing them. Remember to get rid of ants first in order to get rid of aphids. Neem oil or Ludwig's organic insecticide will also do the job!
Avoid using chemical treatment as aphids are food to other beneficial insects and there are more than enough biological ways to get rid of them.