June 1, 2020
Box tree moth help

Not to be confused with Gypsy Moth (which is extremely prevalent in Ontario this year), Box tree moth is a new pest in Ontario that is primarily found on boxwood plants (not in trees). Also, Box Tree Moth has only been detected in and around southern Etobicoke. Home and property owners should take a minute to learn the differences between these two pests, and then report any sightings of only box tree moth using one of two methods below (Step 2).


Box tree moth vs. Gypsy moth

Box tree moth is primarily found on shrubs, not trees. Boxwoods have green leaves and are typically used as hedges.
boxwood shrub in a black potBoxwood sold from a nursery or garden centre in a container.
green leavesClose-up of boxwood foliage (leaves).
front entrance gardenBoxwood is typically used as a hedge and can grow up to 5 feet tall.

Box tree moth vs. Gypsy moth

The Canadian Food Inspection Agency (CFIA) provides Pest Identification Cards that show what each moth looks like.
 
box tree moth pest id card
gypsy moth pest id card

Step 1: Detect

Examine all boxwood plants for signs of chewed leaves, larvae, webbing and frass. Larvae feed from May to September.
tiny cocoonCocoon.
brown leafFeeding damage. Leaves turn brown.
webbing on leavesNote the webbing among chewed leaves.
 
tiny caterpillarYoung larva.
adult mothAdult moth.
adult mothAdult moth.

Step 2: Report a sighting

All findings of box tree moth should be reported to officials who are tracking the pest.

Reports from within the core zone (Toronto, Brampton, Mississauga, Vaughan, Richmond Hill and Markham):
Contact Meghan Greaves at 1-800-265-5656 or 905-875-1805 (ext. 2301)
or email mgreaves@landscapeontario.com.

Sightings from outside the areas listed above (see map):
Contact the Canadian Food Inspection Agency (CFIA) using the link https://www.inspection.gc.ca/about-cfia/contact-us/contact-cfia-online/eng/1299860523723/1299860643049
map of toronto area

Step 3: Take action

If you have the pest there is a biological control spray called Dipel that is registered for control of Box Tree moth.  The active ingredient of the spray is safe to humans and pets and is the same as the one in BTK caterpillar killer sold at most retail garden centres. The same active ingredient is used by the City of Toronto to control gypsy moth.  To kill the larvae, sprays need to be applied when larvae are feeding on leaves, typically from mid-May to mid-June and from mid-July to mid-August and early September.
 
If you wish to hire a professional, we suggest you contact one of these licensed contractors to spray your boxwoods:
 

Tips

  • Box tree moth can be a significant pest if left unmanaged. Spread the word about box tree moth to your local horticultural networking group and encourage others to monitor boxwood for this pest. However, box tree moth can be easily controlled if it is sprayed at the right time. You can still have confidence in planting boxwood in your landscapes.
  • Continue to monitor boxwood plants for signs of active larval stages, especially during the periods of May 30 to June 15, July 15 to Aug. 10 and Sept. 1 to 15.
  • Avoid transplanting boxwood plants from residential gardens within the GTA. Always plant healthy, pest-free, nursery grown boxwood.
  • When removing plants (or clippings): first place a black plastic bag over the plant, cut the main stem at ground level and carefully contain the entire plant inside the bag, tying it off securely.
  • Where air temperatures are 20 C or greater, place bagged plant in the sun for two days to kill any box tree moth inside. (Or bury or burn bagged infested plants, where permitted).

More resources


More information

www.inspection.gc.ca and LandscapeOntario.com/tag/box tree moth
 
If you have any questions, please contact Meghan at:
mgreaves@landscapeontario.com
Toll Free: 1-800-265-5656 ext. 2301
Phone: 1-905-875-1805

 


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