What are Aphids?

Aphids are small, soft-bodied insects that feed on the sap of plants. Typically they will be green or black in colour but can be pink, white or yellow. Some species have a white woolly covering.

There are in excess of 500 different types and many are plant specific. They have a complex life cycle, with both winged and wingless forms. Most concerning is that aphids can also transmit plant viruses from plant to plant.

What Trees do they infest?

They are commonly found on a wide range of plants, and can cause significant damage if their populations become large.

Top of the list for bonsai owners would be Acers, but aphids as a whole are not fussy eaters and infest the vast majority of bonsai including Larch, Pine and many deciduous varieties.

Bonsai Pests Aphids

How to Spot them

  • Aphids are most active during spring and summer, so keep an eye out for them
  • Aphid colonies can be seen with the naked eye, usually on new growth tips, flower buds or the underside of younger leaves
  • It is common to first see ants on your bonsai, they protect the aphids and are rewarded with honeydew
  • You may be able to see the damage caused by aphids in the form of stunted growth or distorted leaves
  • Aphids produce a black sooty mould which grows on the sticky honeydew that the aphids excrete

Non Pesticide Control

  • Firstly, keep your bonsai in good health, a healthy tree is more able to resist the attack of aphids allowing time for natural predators time to move in
  • You can squash aphids using finger and thumb where practical
  • Populations of aphids can build up quickly in spring, use insect glue traps to catch early populations
  • Try to encourage the natural predators of aphids, such as ladybirds, hoverflies, parasitic wasps and earwigs
  • You can purchase natural predators for biological control of aphids in greenhouses, including ladybird larvae, lacewing larvae and several parasitic wasps

Pesticide Control

  • Try using a non-biological washing up liquid mixture to spray the aphids, this will suffocate the insects and their eggs
  • You can treat and kill off overwintering aphid eggs using Vitax Winter Tree Wash between November and February
  • SB Plant Invigorator combines a fatty acid based surfactant and nutrients to stimulate plant growth at the same time
  • You can purchase organic sprays such as Bug Clear Ultra 2, Neudorff Bug Free Bug and Larvae Killer, as well as plant oil based products such as Vitax Plant Guard.
  • For persistent infestations you can use a chemical based insecticide such as Provanto Ultimate Bug Killer or Bug Clear Ultra to break the aphid cycle

Pests & Diseases Products

This product has multiple variants. The options may be chosen on the product page

Pests & Diseases

Vitax Plant Guard Organic


Pests & Diseases

Insect Glue Traps

This product has multiple variants. The options may be chosen on the product page

Pests & Diseases

SB Plant Invigorator