Box Tree Moth in Southern Ontario: Awareness, Prevention & Treatment

At Viking Landscapes Durham, we care about keeping your outdoor spaces healthy and vibrant. Unfortunately, a growing threat has been damaging gardens across Southern Ontario, the Box Tree Moth (Cydalima perspectalis). This invasive pest is a major concern for homeowners and landscapers alike, as it can quickly destroy boxwood hedges, a staple in many gardens.

Understanding the Box Tree Moth

The Box Tree Moth is an invasive species native to Asia, first detected in Ontario in 2018. Since then, it has spread rapidly, posing a significant threat to boxwood plants. The larvae (caterpillars) feed aggressively on boxwood leaves, eventually stripping the plant bare and leading to irreversible damage.

How to Identify Box Tree Moths and Their Larvae

Box tree moths can be identified at several stages of their life cycle, each with distinct features. The eggs are tiny and pale yellow, usually laid in clusters on the underside of boxwood leaves. As they hatch, the larvae appear as green caterpillars with black stripes and white spots. They can grow up to 4 centimeters long and are commonly seen feeding on the leaves. When it’s time to pupate, they form brownish cocoons tucked inside webbed foliage. Adult moths are noticeable by their white wings with a brown border, although some may be completely brown. Spotting these signs early helps prevent serious damage to your boxwoods.

Signs of Infestation

Signs of a box tree moth infestation are often easy to spot if you know what to look for. Leaves may appear skeletonized or go missing entirely as caterpillars feed on the plant. You might also notice webbing or fine silk threads stretched across branches. As the damage progresses, the foliage can start to brown and die back. Keep an eye out for caterpillars or cocoons nestled within the leaves, as their presence confirms active feeding and development. Early detection makes a big difference in controlling the spread.

Prevention: How to Protect Your Boxwoods

Regular Inspections

Check your boxwoods weekly for signs of larvae, webbing, or leaf damage. Early detection is crucial for stopping an infestation before it spreads.

Use Box Tree Moth Traps

Pheromone traps can help monitor moth activity in your area. These traps attract and capture adult male moths, reducing the chances of reproduction.

Keep Plants Healthy

A well-maintained and properly fertilized boxwood hedge is more resistant to pests. Prune dead or infected branches to reduce hiding spots for larvae.

Be Cautious with New Plants

If purchasing new boxwoods, inspect them carefully before planting. The larvae can easily hitchhike on infested plants.

Treatment: How to Control Box Tree Moth Infestations

Manual Removal of Infested Branches

For minor infestations, hand-picking caterpillars and pruning infested branches can be effective. Dispose of them properly to prevent spread.

Biological Control using Bacterial Insecticide

A natural solution is the use of Bacillus thuringiensis var. kurstaki (Btk), a bacterial insecticide that targets caterpillars but is safe for humans, pets, and beneficial insects. Apply as directed, ensuring thorough leaf coverage.

Chemical Insecticides

For severe infestations, contact insecticides like spinosad or pyrethroids may be necessary. Always follow application guidelines to minimize harm to pollinators and other beneficial insects.

Professional Treatment

If your boxwoods are heavily infested, it’s best to call in experts like Viking Landscapes Durham. We’d be happy to offer some advice on protecting your treasured garden.

Stay Vigilant & Protect Your Boxwoods!

The Box Tree Moth is a serious threat in Southern Ontario, but with awareness, prevention, and timely treatment, you can protect your boxwoods from irreversible damage.

At Viking Landscapes Durham, we’re here to help you keep your landscape beautiful and pest-free. If you suspect an infestation or need assistance with treatment, contact us!