Home/Problems/Aphid Infestation
warning

Aphid Infestation

Clusters of small, soft-bodied insects feeding on plant sap from new shoots and leaf undersides. Aphids reproduce rapidly and can cause significant damage if left unchecked.

Symptoms

  • check_circleClusters of small green, black, or white insects on new growth and leaf undersides
  • check_circleDistorted, curled, or puckered new leaves
  • check_circleSticky honeydew coating leaves and surrounding surfaces
  • check_circleBlack sooty mould developing on honeydew
  • check_circleAnts farming aphids on stems

Causes

  • arrow_rightRapid reproduction in warm conditions
  • arrow_rightSoft, lush growth from excess nitrogen fertilisation
  • arrow_rightAbsence of natural predators such as ladybirds and lacewings
  • arrow_rightPlants stressed by drought or nutrient deficiency

How to Diagnose

Clusters of small, pear-shaped insects on new growth are easy to identify. Look for distorted growth and honeydew as secondary signs.

Treatment

Blast aphids off with a strong jet of water. Apply insecticidal soap or neem oil spray to all affected areas. Encourage natural predators — release ladybird larvae if available. Avoid broad-spectrum insecticides which kill beneficial insects.

Prevention

Avoid over-fertilising with nitrogen which produces the soft growth aphids prefer. Encourage beneficial insects by planting flowers near vegetable beds. Check plants weekly during the growing season.