HALIFAX - A ferocious little European invader that's established beach-head colonies in eastern Canada shows signs of spreading to other parts of the country as climate change makes local weather patterns similar to its original home.
The European fire ant is only five millimetres long, but it's aggressive and able to deliver a painful sting that leaves welts that last for days. The ants will swarm invaders in their foraging areas, even humans and pets.
In rural Nova Scotia, colonies of the tiny invaders appear to have exploded in recent years, expanding their range and worrying entomologists.
"I've gone into some areas and you don't hear birds singing or see other insects. There's nothing but fire ants," said Eric Georgeson, a retired entomologist formerly with the Nova Scotia Department of Natural Resources.
Georgeson lives in a rural part of Nova Scotia which has had small colonies of fire ants for decades. But in recent years he's seen colonies grow -- or bud -- into new areas.
"The colonies expand geometrically and they will continue to spread," he said.
Georgeson believes the spread of fire ants is aided by climate change.
Less severe winters mean frost doesn't reach as deeply into the ground as in previous years to kill off established colonies of fire ants. Warmer, humid summers mimic the type of European environment the ants are genetically programmed to thrive in.
"So the ant is saying 'This is like home; where I originally came from'," Georgeson said. "If we don't get colder winters and aren't able to get organized help, the ants will continue to spread."
It's largely left to provinces to monitor the spread of fire ants and there is no co-ordinated plan at the national level to deal with the species. In addition, the small red ants are easy to mistake for benign and indigenous red ants -- sometimes called pavement ants. Fire ants aren't considered a risk to forestry or food crops and are considered a nuisance rather than a pest, placing them outside the mandate of federal agencies.
Like other invasive species such as zebra mussels, brown spruce longhorn beetles and the longhorn beetle, European fire ants probably hitched a ride to North America years ago. It's thought the ants arrived in plants or soil shipped from Europe.
The ants were established in Maine in the early part of the 20th century with two colonies identified before 1950.
The Ontario town of Richmond Hill formulated a management plan in 2006 to deal with a infestation of fire ants. The only other known location in Ontario infested with the invaders is Scarborough. Fire ants have also been reported in New Brunswick and Quebec.
Credits: Canwest News Service