A devastating invasive species may escape Canada’s greenhouses as climate warms
The ant can cause widespread ecological damage.
Wasmannia auropunctata, also referred to as the electric or little fire ant, is a small, golden-brown ant species native to Central and South America.
It has made its way to five continents, including North America. In warmer regions, it invades the wild, outcompeting native ants, preying on native insects and sometimes small animals. The ant can disrupt ecosystems by reducing populations of native species. It’s been called one of the top 100 worst invasive species on the planet, because of the widespread ecological damage it causes.
Its bites are painful, described as feeling like an electric shock or burn, hence their nicknames.
The ants are also an agricultural menace. By protecting agricultural pests like aphids from natural predators in exchange for honeydew — a key food source — they enable pest populations to grow, leading to increased crop damage and reduced yields.
The ant has been found living in Canadian greenhouses. While our climate is currently too cold for it to spread outdoors, a recent report from the University of Toronto suggests the little fire ant, along with several other non-native ant species currently living in Canadian buildings, could venture outside as global temperatures rise.
“We tend to think of non-native species invading outdoor environments only,” Toby Tsang, a postdoctoral researcher in the department of biological sciences at U of T Scarborough and lead author of the study, says in a statement.
“But indoor environments – like homes, buildings, and greenhouses – can act as safe havens for non-native ants, especially in colder regions where they wouldn’t normally be able to survive outside.”
Tsang and his team examined 323 non-native ant species from 477 regions to determine how climate influences the ants’ decision to remain indoors. Their model found 2-4°C of warming could entice ants to move outside, making them more likely to become established in Canada.
Many of the ants likely made their way into Canada through shipping containers.
Ontario is currently housing five non-native ant species, but only indoors. The little fire ant is one of them.
Tsang hopes his research will draw more attention to the risks associated with indoor non-native populations, something that he says invasion programs often overlook.
“Some of the ants that are most likely to spread can be very harmful, such as the [little fire ant],” he says.
“These species can outcompete and prey on native species, cause ecological and agricultural damage, and even pose health risks to humans. We need to pay better attention to them.”
Header image: File photo of a little fire ant biting a human. (Plegadis/Wikipedia Public Domain) Graphical elements added by Cheryl Santa Maria for The Weather Network.