Box tree moth

The box tree moth (Cydalima perspectalis Walker) is a serious pest affecting boxwood plants (Buxus spp). It does not pose a risk to human health. Boxwood plants are important when it comes to nursery trade between Canada and the United States and are a major part of Canada's landscape.

Box tree moth spreads primarily through the movement of infested boxwood shrubs and can fly an estimated 5-10 km per year.

What you can do

From May to September, inspect your boxwoods for signs of box tree moth. Adults, pupae, mature larvae and leaves with eggs on them can all be removed by hand and destroyed by placing them in soapy water, alcohol or an air tight sealable container. These life stages are not easily controlled through treatments.

Larvae that are feeding on boxwood plants can be controlled with a biological pesticide containing Bacillus thuringiensis subsp. kurstaki. Multiple treatments may be necessary. Consider contacting a local landscaping company for help with treatment.

If you think you have spotted a box tree moth or signs of infestation on a boxwood shrub outside of Ontario, report it immediately.

Report a box tree moth sighting outside of Ontario

Where it is

Box tree moth is a regulated pest in Canada. It is established in Ontario in the areas between Toronto and Windsor, and Toronto and Niagara. In Canada, this pest is found exclusively on boxwood shrubs.

In the summer of 2023, box tree moth was additionally confirmed on residential properties in Quebec, Nova Scotia and New Brunswick. Ontario, Quebec, New Brunswick, Nova Scotia, and Newfoundland and Labrador are considered the areas regulated for box tree moth in Canada.

What to look for

Life stages of the box tree moth

Eggs
Larva
Pupa
Adult

Signs of infestation on boxwood plants

Infested boxwood plant
Healthy boxwood plant

Signs of box tree moth include chewed leaves, larvae, webbing and sawdust-like debris (frass).

What we are doing

In the summer of 2023, box tree moth was confirmed on residential properties in Quebec, Nova Scotia and New Brunswick. In response to these detections, the CFIA consulted the public on options to expand the regulated area from January 11 to February 10, 2024. After analyzing the comments received, the CFIA has decided to add the provinces of Quebec, New Brunswick, Nova Scotia, and Newfoundland and Labrador to the area regulated for BTM. Directive D-22-04 and the Ministerial Order have been revised to reflect the expanded area.

Buxus spp. plants for planting may move freely within, and between, the provinces of Ontario, Québec, New Brunswick, Nova Scotia, and Newfoundland and Labrador.

Box tree moth was added to the List of pests regulated by Canada. Consult the Pest risk management decision (RMD-22-02) to understand why this decision was made, and the directive for box tree moth (D-22-04) for a description of domestic and import phytosanitary requirements.

A Ministerial Order under the Plant Protection Act was established in July 2023 to support enforcement of these regulatory requirements, which include movement restrictions for boxwood shrubs. Ontario is declared a place infested with box tree moth.

Collaborative surveillance and community science continue in an effort to reduce the risk of spread in Canada. A national technical advisory committee has been established to discuss next steps and raise awareness of box tree moth with industry and the public. Members currently include the CFIA, the Ontario Ministry of Agriculture, Food and Rural Affairs, Landscape Ontario, Canadian Nursery Landscape Association, Ministère de l'Agriculture, des Pêcheries et de l'Alimentation, Québec vert, and grower representatives.

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