Trees

Aphids

What is an aphid?

Aphids are small, soft-bodied insects that feed by sucking nutrient-rich liquids, such as sap, out of plants. They thrive in dry, hot weather.

How do I protect my trees from aphids?

There are a few ways to help reduce aphid populations and protect your trees: 

• Dislodge aphids with a hard jet of water, ensuring to spray under leaves and into the middle of the canopy. This is best done in morning or late evening.
• Use a product such as Tanglefoot of Stik-em to apply a sticky band around the trunk of the tree to restrict insect movement. Place a protective band under the sticky product first.
• Prune any branches that touch the ground, other plants, or buildings.
• Avoid over fertilization and choose slow-release options. High nitrogen levels favour aphid reproduction and too much fertilizer promotes succulent new growth which attracts aphids.
• Encourage natural aphid predators such as birds, spiders, ladybugs, lacewings, hover fly larvae, and parasitic wasps. 

Western hemlock looper moths

What is a looper moth?
The western hemlock looper moth is a native insect species in Port Moody that feeds on
trees such as western hemlock. Looper moths cause tree defoliation which, during outbreaks, can result in severe damage to local forests.

How long does a looper moth outbreak last?
Outbreaks occur every 11-15 years and each outbreak can last one to three years.

Can the outbreak be controlled?
There are not any control methods that are practical to control looper moth outbreaks. Current best practice is to let the outbreak naturally run its course, which usually occurs within three years.

Which trees do looper moths damage?
Looper moths typically feed on western hemlock trees. However, during outbreaks when populations are high, the moths will also feed on douglas fir, western red cedar, and spruce.

Will trees die?
Some trees do not tolerate defoliation and may succumb to the damage. Western hemlock in particular is sensitive to defoliation and tree mortality is common.

Are dead trees a hazard?
Generally, the trees were healthy before defoliation caused death. It will require years of decay before the trees become structurally weak.

Trees that have pre-existing structural defects may need to be removed if there is a risk to nearby people or structures. You can report hazardous trees through our online form or by calling our Operations Centre at 604-469-4574.

What is the impact to forest health?
Looper moths provide a natural and important role in forest ecosystems. By killing susceptible trees, nutrients are recycled and younger trees are able to emerge.

Tree topping

What is tree topping?
Tree topping is the practice of cutting and removing the tops of healthy trees with the intention of reducing the tree’s height. However, it is not considered a viable, long-term pruning method and can negatively impact the health of trees.

How does tree topping impact the health of a tree?
When topped, trees suffer from multiple large wounds and are often unable to prevent fungi from entering them. This can severely weaken or kill the tree.

To survive topping, trees may produce numerous shoots below each topping cut. These shoots grow rapidly and may reach up to 20 feet in one year. Although regrowth is quick, the new shoots do not have structural integrity of the original branches. They are prone to break and are especially vulnerable during wind storms.

Does the City top trees?
No, the City does not practice tree topping.

What is an alternative to tree topping?
A professional arborist can be consulted and hired to determine the type of pruning necessary to maintain or improve the health, and safety, of your tree.