Canadian Pacific orders to dismantle and remove community gardens along the Arbutus Corridor could be delayed by an infestation of European fire ants in the garden plots near East Boulevard and 68th Avenue.
These tenacious pests are nearly impossible to eradicate and are being spread throughout southwestern B.C. by the movement of infested plants and soil, said Rob Higgins, a biologist at Thompson Rivers University.
About 30 colonies have been identified near the CP rail right-of-way in Kerrisdale, but the rest of the corridor should be surveyed before any plants or soil are removed, he said.
“I just this morning sent emails to entomologists with the City of Vancouver and the province,” he said. “I’m very concerned about [CP’s] request to remove soil from the community gardens. We don’t have a way to control them yet, so we really don’t want to make the situation worse.”
In the four years since European fire ants were first discovered in B.C., their presence has been confirmed in at least 25 locations throughout Metro Vancouver and the Fraser Valley.
Fire ants are well established in Delta, Maple Ridge and Chilliwack, as well as Victoria and Courtenay. Colonies have recently been confirmed in Coquitlam and Surrey.
“These ants typically spread very slowly,” said Higgins. “They can only really move around when we help them by moving soils and plants along the rail line.”
CP has issued a July 31 deadline to community gardeners along the Arbutus Corridor to remove plants, gardens and structures that encroach on the railway’s right-of-way. Dozens of plots are partly or entirely within the right of way, according to maps distributed by the company.
Higgins worries that dozens of new infestations could take hold if gardeners move soil or transplant prized plants in new locations.
“The area between 66th Avenue and 68th Avenue near East Boulevard is quite heavily infested, but we haven’t sampled in other areas so I don’t how many other community gardens along the corridor might be affected,” Higgins said.
A CP environmental expert will consult with Higgins on the threat before any further action is taken by the company, according to CP spokesman Ed Greenberg.
“Our railway will be developing an appropriate plan to address the situation,” said Greenberg.
In the meantime, the removal order remains in effect, he said.
“It’s important that the gardens that are infested with fire ants not be moved or it could spread the infestation,” said Sadhu Johnston, deputy city manager of the City of Vancouver.
“We are dealing with fire ants in a number of locations outside the Arbutus Corridor and at this time there are no effective methods to eradicate fire ant infestations,” he said.
The city is posting signs in the area of the known infestations instructing gardeners that plant roots should be free of soil if they are being removed and that no soil should be removed from the area.
Sadhu stressed that the property belongs to CP and is not under the city’s jurisdiction.
Though tiny, fire ants swarm very quickly when disturbed and deliver a painful sting. Eradicating these ants with chemical means has not been successful and removing colonies from an infested area can take years.
The nests can be dug up and removed during the winter months when the ants cluster together into a ball the size of a fist. But it may take several winters to completely remove all the nests in an infested area.