Aphid infestations and aphid control

Aphids on Trees

Aphids are tiny soft-bodied insects that suck the juices from plant leaves.

They rarely threaten tree health, but can become a nuisance due to the sticky honeydew which drips from infested leaves.

You may also notice ants on aphid-infested trees. Ants feed on the sugary honeydew and do not cause any damage to the tree.

Most aphids can only feed on one species of plant or shrub. Because of this, aphids infesting trees on City boulevards and streets will not infest other types of plants on your property.

Aphid control

The City is concerned about aphid problems and is implementing the use of biological controls to reduce aphid infestations.

The biological controles include using predatory insects, such as ladybeetles, to control aphids.

Many predators already do a very good job of controlling aphids on street trees.

There is usually a time lag of between 1 and 3 weeks before predator populations catch up with aphid populations. Predators can then become so numerous on leaves that many people mistake them for pests themselves.

What you can do about aphids infesting your trees

For small trees, it may be helpful to blast badly affected leaves and branches with a jet of water in the evening.

This physically dislodges and kills the delicate aphids but should not harm predators.

Related links

Integrated Pest Management

The City of Vancouver was the first municipality in Canada to adopt an Integrated Pest Management (IPM) approach to managing pest infestations. The program has allowed us to reduce, and in some cases even eliminate, our dependence on pesticides. Read more about the IPM program.


The City maintains trees that line Vancouver’s streets and trees in parks. Request tree pruning, planting, removal, and pest control.