Pest Issues

Oak Wilt

There are at least 9 species of oak trees in the City of Windsor. All of these species are susceptible to infection by the Oak Wilt fungal disease.

Windsor has over 1,300 Oaks trees on City streets. Many more are located on private lands and in our natural area parks such as Black Oak Heritage Park. Oaks make up over 10% of the city’s tree canopy cover.

Oak wilt is a vascular disease of oak trees, caused by the fungus Bretziella fagacearum. The fungus grows on the outer sapwood of oak trees, restricting the flow of water and nutrients through the tree and causing the foliage to wilt. While some trees can recover from the infection, the fungus can eventually cause the tree to die. The group of oaks known as ‘Red’ oaks are considered slightly more susceptible to the disease than are the ‘White’ oak group. 

Oak wilt is not present in Canada, but it occurs in U.S. states in close proximity to Ontario. The origin of the fungus is unknown. In 2019, the Canadian Food Inspection Agency (CFIA) announced that the DNA for oak wilt was found on insect samples collected in Canada.

If you suspect an Oak Tree in the City of Windsor has Oak Wilt, contact the Canadian Food Inspection Agency. 

Actions to protect against Oak Wilt in Windsor

  • Forestry has mapped out the locations of our known oak trees along city streets and in most of our urban parks. During those periods of the year when the life cycle of the disease and the insect carriers for this disease are active, Forestry crews monitor the city-owned trees for signs and symptoms of oak wilt. Forestry staff have attended courses and been trained to recognize and identify the disease. 
  • The City has cooperated with researchers and inspectors from the CFIA and Natural Resources Canada in monitoring for the insects and the disease.
  • Oak trees are one of our most important native species and, as such, are a species included in our tree planting programs. In recent years, the program has shifted focus away from red oaks and concentrated more effort on working with white oak trees.
  • Forestry has also modified our requirements for tree maintenance activities to protect oak trees. The insects that may carry the disease are known to be attracted to fresh wounds or cuts on oak trees. Therefore, Forestry has instigated a moratorium on all trimming and cutting of Oaks from March 31 through to the end of October each year, except in cases of emergency of storm damage repair. If trimming or cutting is required, then all wounds must be painted over immediately with tree wound sealant or latex paint. Logs and brushes must be processed into wood-chip mulch as soon as possible. Stumps must be initially painted and then removed and roots covered as soon as possible.
  • If you suspect issues with an oak tree, please call the city’s 311 Service Line and request a tree inspection.
  • For more information on Oak Wilt visit: Oak Wilt – Invasive Species Centre

Emerald Ash Borer (EAB)

Although still present in the region, EAB is not considered a significant threat at this time, largely because the vast majority of local ash trees have been lost since the infestation began in 2006.Emerald Ash Borer

The emerald ash borer (Agrilus planipennis) is a non-native insect that poses an enormous threat to our urban and rural forests.  The emerald ash borer (EAB) kills ash trees by feeding under the bark and disrupting the flow of nutrients and water throughout the tree.

The beetle's identity was confirmed in Windsor, Ontario in July 2002.  It is speculated that the emerald ash borer was introduced to Canada via wooden shipping crates. The emerald ash borer attacks ash, walnut and elm trees in its native lands of China, Mongolia, Korea, Japan, Taiwan and the Russian Far East.  In Canada, only ash trees appear to be attacked and killed.  All 16 native ash species are susceptible to this insect.

 A further detailed description of the emerald ash borer and its life cycle is available. View information on the Emerald Ash Borer on the Canadian Food Inspection Agency website or at the Ministry of Natural Resources website. 

 Action Against Emerald Ash Borer 

  • The Canadian Food Inspection Agency has the responsibility for dealing with the emerald ash borer. The City of Windsor is responsible for trees on public property and in parks.
  • Ground surveys were conducted to determine how far the emerald ash borer has spread, and Windsor/Essex County/Chatham Kent, as with much of Ontario, has been placed under quarantine.
  • Signs were placed on all roads leading into and out of the quarantine zone and at all Canada Customs entry points from Sarnia to Pelee Island.  Amnesty firewood bins have also been placed at the borders, for the public to deposit infected wood.
  • Presentations and information packages were given to all Ontario municipalities in the infested area.
  • Mass media have been used to inform the public of the problem. This includes local and some national television, local and national radio, newspapers, posters, flyers, brochures, a telephone inquiry line and online information at the Canadian Food Inspection Agency website.

For more information on the Emerald Ash Borer visit: Emerald Ash Borer - Invasive Species Centre

Other Pests Being Monitored in Windsor

Bagworms

Bagworms have been reported in various locations across Windsor since approximately 2008. This pest has been commonly found on locust, white cedar and spruce trees. Both manual and chemical options exist for the control of this pest, depending on the severity of the local infection. The City continues to monitor and has conducted localized control operations when required.

For more information on Bagworm, visit: Bagworm

Spongy Moth (formerly known as 'Gypsy Moth')

Forestry staff monitor local populations for this pest. In recent years, as with much of Ontario, there has been a moderate outbreak of this insect pest. The city did conduct local egg mass surveys as well as sanitation operations to remove egg masses in several local parks. Staff will continue to monitor.

For more information on Spongy Moth, visit: Government of Canada.