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Fire ant invasion sparks call for soil moving controls
A researcher tracking the spread of European fire ants says the tiny, stinging pests have likely burrowed into most communities in Metro Vancouver, the Fraser Valley and southern Vancouver Island.
Thompson Rivers University biology professor Robert Higgins said he has positively identified fire ants in Chilliwack, Maple Ridge, Delta, Richmond, Burnaby, Vancouver, North Vancouver, Victoria, Oak Bay and Courtenay.
They were first identified in 2010 in the District of North Vancouver and can render parks unusable for purposes like picnicking, camping and lounging on the grass.
"They're coming in on landscaping plants and soil that have been shipped from out east," Higgins said. "And now that they're established here, we're moving them around internally."
He's urging anyone doing landscaping to reject any plants or soil with ants of any kind on them to minimize the risk of further spread.
And Higgins says the province should explore options to regulate the movement of soil from property infested with fire ants.
He's not predicting whether the species can be eradicated, but said the top priority is keeping them new neighbourhoods from being colonized.
Jennifer Grenz, development and projects manager for the Invasive Species Council of Metro Vancouver, says European fire ants pose a significant health and safety risk worse than other invasive pests, such as chafer beetles, which merely ruin lawns aesthetically.
Fire ants are ultra-sensitive to ground movement and quickly swarm people and pets that walk nearby.
"We've been in situations where it looks like a volcano of ants erupting out of the ground," Grenz said. "They bite you and they hang on and then they bite you multiple times. By the time you notice something on you, you've probably got many."
Large numbers of stings can lead to severe medical reactions, especially in infants, neurologically compromised people and the elderly.
"This isn't just another invasive species in my mind."
A residential infestation hurts property values, she said, adding homeowners react in some cases by decking over their entire yard to reclaim some use of it.
Dogs can get badly stung, Grenz said, and she's concerned ground-nesting birds may also become victims as fire ants spread.
The ants have appeared in VanDusen Botanical Garden in Vancouver, at a garden centre on Marine Drive in south Burnaby and, most recently, in Richmond at McDonald Beach Park, where signs advise visitors to "avoid remaining stationary."
Grenz said digging up ant nests in winter, when they're more compact, coupled with the spread of diatomaceous earth, shows some promise in eliminating fire ants.
Higgins is also trying to lure ant colonies to relocate into plastic pipe traps.
Grenz would like to conduct a Metro regional survey to better gauge where fire ants are entrenched.
But she also wants the province to pursue legislation to stop ant-infested soil dug up at contaminated development sites from being moved to other properties.
"We need to stop the movement of contaminated material," Grenz said. "If we don't get on the soil movement issue, there's going to be ants all over the place. There isn't anywhere in the Lower Mainland that they couldn't potentially go to."
– with files from Martin van den Hemel
European fire ants on a dead snake at McDonald Beach Park in Richmond.