The European fire ant (Myrmica rubra Linnaeus), is an invasive, non-native species that is a nuisance pest for people and a potential threat to the environment. Over the past 10 years, they have been found in residential and natural areas in the Greater Toronto Area, including parks and natural areas in Markham.
European fire ants live in moist, shaded, natural areas. Unlike native ants, they do not nest in large mounds, but rather within decaying logs and leaf litter.
Parks staff discovered very few or no European fire ants present in open and sunny areas such as sports fields and playgrounds.
However, colonies were found in areas along forest margins or fields with tall vegetation, and along fence lines between yards and natural areas (mostly underneath or in discarded yard waste, such as grass clippings, leaf piles, potted plants). Some colonies were present in natural areas underneath fallen branches.
European fire ants aggressively defend their territory and will sting humans, pets, and wildlife. Their sting is equivalent to that of a bee or wasp. The severity of the sting varies from one individual to another but typically causes an initial burning sensation. Affected areas can remain sore from a few hours up to a day or more.
In rare cases, anaphylactic shock may occur, which requires immediate medical attention.
What you need to know
CAUTION: If you come in contact with the European fire ant, swipe it away from your skin and do not attempt to crush them. This will only provoke them to sting.
Native ants, which are an important part of our ecosystem, construct their nests in the soil and build visible mounds. European fire ants do not build mounds, which make the nest more difficult to find.
Characteristics of the European fire ant:
- Reddish-brown in colour with darker pigmentation the head.
- Waist has two segments while most native ant species have only one.
- Two backward pointing spines on the thorax visible only with a magnifying glass.
European fire ants are not the same fire ants found in the southern American states. Those ants have a more severe sting and are not present in Markham.
There are no known effective, long-term control methods available for parkland. Known treatments will kill beneficial insects too, which can negatively affect wildlife and the natural food chain.
When travelling through Markham parklands, you're advised to:
- Stay on designated pathways and trails.
- Always wear covered footwear and long pants to protect yourself from ant stings and other hazards - different insect bites or poison ivy.
- Keep dogs leashed and on the designated trail.
Keep your property clean to avoid a potential European fire ant habitat:
- Disposing of yard waste properly. Do not dump yard waste into natural areas.
- Keep the area immediately adjacent to your property clear of accumulated branches or decaying vegetation.
- Avoid transporting materials (soil, mulch, plants, and decaying logs) unless you are certain that it is free of fire ants.
If you discover an infestation of European fire ants on your property, treat the colonies quickly to reduce their opportunity to expand into neighbouring areas.
Try using boric acid bait traps, diatomaceous earth, or pyrethrin (these products can be purchased from local nurseries and hardware stores and should be applied according to product instructions) or contact a pest control company.
The European fire ant is native to Europe and northern Asia. They were first discovered in North America in 1908 along the coast of Maine. It is likely that they arrived by infested containerized plants brought from Europe.
Read more about the European fire ant from the following online sources.
This information was prepared in collaboration with Toronto and Region Conservation Authority. Research assistance was provided by Kristi Rudmik of York University. Research is being undertaken by New Brunswick and Maine Universities. (Photos courtesy: University of Maine)