Summary

• Spongy moths are an invasive species destructive to forests and farms
• The Province will spray 36 hectares around Beach Grove in Delta, and 121 hectares in Squamish west and south of the intersection of Buckley and Third avenues  
• The treatment has been approved for use by Health Canada
• Treatments will occur between late April and June 30, 2026, weather depending

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The Province will conduct aerial-spray treatments from late April until June 30, 2026, in Delta and Squamish to eradicate spongy moths and minimize the risk they pose to forests, farms and trees.

The following areas will be treated in accordance with B.C.’s Integrated Pest Management Act:

• Delta: 36 hectares – in Beach Grove by Boundary Bay, in the area of 16 Avenue and 17A Avenue, and Beach Grove Road
• Squamish: 121 hectares – west of the intersection of Buckley Avenue and Third Avenue, to the edge of the Squamish River, and to just south of Vancouver Street.

Spongy moths are a serious threat to forests and farms

B.C.’s ecosystems and economy are at risk from invasive spongy moths, Lymantria dispar, (formerly known as gypsy moths). Spongy moth caterpillars pose a serious pest as they feed on tree leaves, resulting in defoliation of forests, parks, crops and residential areas.

Without treatment, spongy moths can spread to other areas of B.C. This can lead to serious damage to agriculture and forestry products that are imported and exported.

Treatment areas and products are based on years of experience and study

• Treatments occur only when necessary, as determined by survey with pheromone-baited moth traps.
• In Delta and Squamish, moth numbers have been increasing for more than two years.
• Without an eradication program, it is highly likely spongy moths will become permanent in the province, which will lead to significant trade implications for agriculture and foresty businesses in B.C., and an increased risk of ecological damage.

The active ingredient

• The active ingredient in the treatment, Bacillus thuringiensis var kurstaki (Btk), is naturally present in soil.
• Btk is used in organic farming for control of caterpillar pests.
• Btk affects only the stomachs of caterpillars. It has no effects on people or pets, birds and other wildlife.
• The treatment has been approved by Health Canada for the control of spongy moth larvae since 1961. It has been applied in B.C. since 1979, most recently in 2024.
• The Province has been issued Pesticide Use Permit No. 924-0001-26-26 to treat spongy moths by aerial application with Foray 48B, which contains the active ingredient BtK on all residential, commercial, federal and public lands within the treatment areas.

Three applications will be required. Each application is expected to start after first light and end before 7:30 a.m. Changes in weather conditions may cause delays or cancellations with short notice. Each application will be seven to 10 days apart. 

People who want to minimize their exposure during the application may remain indoors with their windows and doors closed during the treatment and for at least an hour after. In addition to staying indoors during spraying, it is recommended to follow standard good-hygiene practices, including washing hands after any outdoor activities and washing all fruits and vegetables gathered from the treated areas before consumption. 

Information about health lines and websites can be accessed on the spongy moth website, where people can obtain spray-related information or report human health or environmental health-related concerns associated with the pesticide use.

Multilingual health information is available through HealthLinkBC by calling 811.

Learn More:

• To learn about Spongy moths and the treatment program, call: 1-866-917-5999, toll-free, or visit: https://www.gov.bc.ca/spongymoth
• For information about the pesticide-use permit application, to see a map of planned treatment areas or to subscribe to receive notifications and program updates via email, visit: https://www2.gov.bc.ca/gov/content/industry/forestry/managing-our-forest-resources/forest-health/forest-pests/spongy-moth/news