Cankerworm

Fall cankerworm has been identified in the following locations in Newmarket:

Bogart Creek near Srigley Street
D'arcy Street and Church Street

View the map below for details on the affected areas.

What is the fall cankerworm?

Cankerworms naturally occur every seven to 10 years and last for two to three years. They hatch in the spring and feed for five to six weeks before dropping from the trees on silk strands. They spend the next four-five months of their lifecycle underground. The adult moths emerge in late September to October and lay eggs in the tree canopy.

What damage can the fall cankerworm cause?

Damage is caused by the larvae chewing small holes in developing leaves on trees. As the feeding continues, these holes become larger, only leaf veins and midribs remain.

Why is there a larger population of fall cankerworm this year?

The warmer-than-normal winter may have resulted in the widespread of fall cankerworm in Newmarket and other neighbour municipalities such as the City of Toronto, City of Hamilton and the City of Mississauga.

What types of trees are currently Affected?

Manitoba Maples and Silver Maples

What is the Town doing about the fall cankerworm?

We are monitoring the scale and scope of the infestation to determine the appropriate steps to take to control the cankerworm population.

My privately owned tree has fall cankerworms, what should I do?

We suggest you contact a certified arborist to help assess the scale and scope of the infestation. A list of certified arborist can found from the Ontario International Association of Arborist.

What are some ways to treat cankerworms?

There are a number of ways to treat this insect, one is in the fall when the adults come out to lay their eggs. The female moth is flightless and can be captured by banding trees with sticky tape thus reducing the amount of eggs laid or using a natural pesticide with an aerial application – this needs to be completed mid-September to ensure its effectiveness.