Invasive Species

An invasive species is an introduced species to an environment that becomes overpopulated and harms its new environment. Invasive species can adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage.

Please see below for information about invasive species in Niagara-on-the-Lake. 

Oak Wilt

Oak wilt is caused by a fungus particularly susceptible to Red Oaks and spreads naturally through root grafts or beetles carrying fungal spores.

The Canadian Food Inspection Agency (CFIA) has confirmed a case of oak wilt in Niagara-on-the-Lake, making this the third confirmed case of oak wilt in Ontario.

The public can also help slow the spread of oak wilt by reporting any suspect finds to the CFIA. To report a suspected detection or for updates about oak wilt, the public can visit

Frequently Asked Questions about Oak Wilt

Spotted Lanternflies

The Spotted Lanternfly is a sap-feeding planthopper originally from Asia. Adult Spotted Lanternflies are large (2.5 cm in length) and brightly coloured. Spotted Lanternflies can weaken or kill plants by feeding on sap and excreting sugary honeydew, which promotes the development of sooty mould.  

In accordance with the directives from the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), who has been monitoring Spotted Lanterflies since 2016, Spotted Lanternfly Traps have been installed to safeguard Niagara-on-the-Lake's plant population. The trees, located in Old Town, were selected by OMAFRA and Town Staff. The species and locations were considered ideal candidates for the Spotted Lanternfly.

If you encounter a Spotted Lanternfly, please take pictures and report them immediately to the Canadian Food Inspection Agency at

Frequently Asked Questions about Spotted Lanternflies

Japanese Knotweed

Japanese knotweed is native to eastern Asia and was introduced to North America as a horticultural plant in the late 19th century. It can grow in a wide range of habitats, including riparian areas, wetlands, roadsides, ditches, and fence lines. It forms dense thickets of bamboo-like vegetation that aggressively outcompetes native plants and negatively impacts wetland and riparian areas. This invasive plant has hollow, smooth, purple to green-coloured stems up to 2.5 cm in diameter.


Invasive Species Center - Japanese Knotweed

Ontario’s Invading Species Awareness Program – Japanese Knotweed

Japanese Knotweed – Best Management Practices in Ontario

Frequently Asked Questions about Japanese Knotweed

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