Moose Jaw is Being Infested with Cottony Ash Psyllid


MJ Independent

The City of Moose Jaw is under attack. It's being infested by of a Cottony Ash Psyllid;  a small winged insect that affects Manchurian (mancana) and Black Ash trees as well as
their hybrids and is considered invasive by the Saskatchewan Invasive Species Council.

The dreaded Cottony Ash Psyllid

The dreaded Cottony Ash Psyllid

The Manchurian and the Black Ash trees can be identified by their opposite bud arrangement, large compound leaves and large black buds. "

The trees in Moose Jaw’s downtown core are predominantly Manchurian Ash" said Sarah Regent, Parks Gardener for the City. 

Currently, the city is attempting to control the Cottony Ash Psyllid and reduce the stress on trees by spraying them with an insecticidal soap. 

Homeowners with Manchurian or Black Ash trees on their property are being warned to  monitor their trees for signs and symptoms of Cottony Ash Psyllid.

Signs and symptoms include curled, distorted leaves, a sticky, white substance resembling cotton, sticky surfaces below the tree, and a reduced number of leaves on the inner branches.

Homeowners should reduce stress on susceptible trees by watering deeply during hot, dry weather, reducing other pests, not using herbicides underneath the tree, and preventing trunk and root damage.

Trees already infested with Cottony Ash Psyllid may be sprayed with insecticidal soap or an insecticide registered for use on trees at bud break, approximately the last week of May to first week of June, or at the emergence of adult psyllids in July.

"Spring insecticide treatments are most effective, but summer treatments are useful to protect leaves that have not yet been distorted" said Regent, adding that one should always read and follow label directions when applying a pesticide or hire a professional applicator.

For more information please contact the Parks & Recreation Department or