The first aerial-spraying treatment to eradicate invasive gypsy moths from 231 hectares of residential and municipal park land in Lake Cowichan will occur next week, weather permitting.

The gypsy moth is destructive to native and urban forests and orchards. Without treatment, it could spread to other parts of the province and put hundreds of species of trees and shrubs at risk, including endangered Garry oak ecosystems.

Spraying will take place from the forest south of Hammond Road, north to the Cowichan Valley Highway, west to Fen Road and east to Boundary Road.

Spraying will start shortly after sunrise (approximately 5:50 a.m.) and should be completed by 7:30 a.m. daily. Up to four separate treatments are required this spring. Unless delayed by poor weather, each treatment is expected to take one to two mornings to apply. The first treatment will take two mornings. The ministry aims to complete spraying by mid-June.

The spray area will be treated with Foray 48B, which contains Bacillus thuringiensis var kurstaki (Btk). Btk is an organic, natural agent that has been approved for the control of gypsy moth larvae in Canada since 1961. Foray 48B and other Btk formulations received certification for acceptable use on certified organic farms by the Organic Materials Review Institute of Canada in April 2018.

Btk is naturally present in urban, forest and agricultural soil throughout the province. It does not harm humans, mammals, birds, fish, plants, reptiles, amphibians, bees or other insects and affects caterpillars only after they have ingested it.

The spray will be applied by a low-flying plane. Residents within and adjacent to the treatment area will likely hear the aircraft at some point during the treatment. The spray equipment is GPS-calibrated and controlled. Spraying will occur only when the plane is immediately over the treatment area.

Anyone wishing to minimize contact with the spray material may choose to remain indoors with their windows and doors closed during the treatment, and for at least 30 minutes after. Pets or livestock that may be frightened by the aircraft should be secured or brought indoors.

Poor weather or wind may cause treatments to be postponed with little advance notice, and the treatment will resume the next suitable morning.

A telephone line is staffed during business hours and provides up-to-date spray schedules and recorded information 24 hours per day, toll-free, at 1 866 917-5999. Individuals subscribed to gypsy moth email updates will receive automatic program updates. To subscribe, visit: www.gov.bc.ca/gypsymoth

Learn More:

To learn more about gypsy moths, visit: www.gov.bc.ca/gypsymoth

For health information any time, call HealthLinkBC at 811, toll-free and available in more than 30 languages. HealthLinkBC services for the deaf, hard of hearing and speech impaired are available by calling 711 for TTY or 604 215-5101 for video relay service.

Health information on gypsy moth spraying in eight languages is available at: https://www.healthlinkbc.ca/healthlinkbc-files/gypsy-moth-spraying

Dr. Richard Stanwick, chief medical health officer of Island Health, discusses gypsy moth spray-treatment programs: https://youtu.be/FzTSmsxkJtc