Central Okanagan  

Webworm returns to Okanagan

The fall webworm has begun its semi-annual appearance in the Okanagan.

These webworms are commonly seen in the late summer or early fall and while they can be unsightly – with webs that are often confused with the more destructive tent caterpillar – they rarely cause any permanent harm to the trees in which they nest. 

Fall webworm populations normally rise and fall from year to year, and populations seem to be peaking this year.

The City of Kelowna’s Park Services team does not apply pesticides against it, as the fall webworm is primarily an esthetic problem and not a threat to trees.

In some circumstances, City gardeners will prune out small webs and destroy them by submerging them in soapy water, but mainly the fall webworms’ natural predators will bring the insect under control.

Residents can remove the webs in a few different ways including pruning, blasting with water or by poking the web (with a pole or stick) and exposing the fall webworm to its predators.

The City asks that residents do not put pruned web into “green” bins as yard waste because it can further the spread of the fall webworm to new areas.

If residents wish to apply a biological pesticide on their own trees, Btk (Bacillus thuringiensis var. kurstaki) is an excluded pesticide from the Pesticide Regulation Bylaw No. 9920. Residents are reminded to follow all label instructions when applying any pesticide.

For more information about pest management, visit kelowna.ca/parks.


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