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Province plans spring sprayings to prevent invasive spongy moths in Greater Victoria

The insects pose a threat to trees, crops and the economy, ministry says
The province will be spraying spongy moth insecticide at seven sites around Vancouver Island in the spring to prevent the invasive species from becoming established. (Black Press Media file photo)

The province will be spraying natural areas across Vancouver Island in the spring in an attempt to stem the impact of increasingly pervasive invasive spongy moths.

The Ministry of Forests plans to carry out a spongy moth treatment program in Greater Victoria, Courtenay, Campbell River and Port Alberni as the province says they pose a risk to ecosystems and the economy.

Garry oak, arbutus, red alder, aspen, cottonwood, maple, orchard fruit trees, nut trees and other urban trees could be impacted should the moths become permanently established, the province said.

A record number of male spongy moths were trapped across B.C. last year and an increased number has been detected at seven identified treatment sites over the past three years.

The ministry will be conducting pesticide spraying at those seven locations to prevent the moths, which have defoliated forest sections in Ontario and the U.S., from becoming a mainstay in the areas. Three planned aerial treatments will occur between April 1 and June 30.

“Local pollinators that rely on these trees face increased competition from spongy moth caterpillars for resources,” the forests ministry said in a release. “Untreated spongy moths risk spreading to other areas of B.C. and are a threat to forests and farms.”

Those permanent moth population impacts on forests include B.C.’s farm and forest exports being subject to restrictions before crossing into the United States.

The insects, called Lymantria moths and formerly known as gypsy moths, are also a risk to agricultural operations as they can affect crops like apples, blueberries, other fruits and nursery products. Infested farm operations could be subject to agricultural quarantines, additional certification measures and increased pesticide use, the province said.

The spongy moth threat in B.C. is tied to outbreaks in Ontario and the U.S. in recent years. The moth eggs commonly make their way to the west coast on recreation vehicles and outdoor household objects.

The ministry will use a biological insecticide that’s used in organic farming and is naturally present in soils throughout the province. The province said the insecticide specifically affects the digestive system of spongy moths, while it poses no threat to people, animals and plants.

More information on the seven aerial spraying sites can be found at

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