Gaining ground in fight against Naramata’s fire ants

NARAMATA – A biologist from Thompson Rivers University has made some progress in his battle to stop an invasive species of fire ant from gaining a foot hold in the South Okanagan.

Dr. Robert J. Higgins and assistant Naomi Harder have been working to find an effective method of eliminating the invasive species discovered in Naramata in 2013, and while not completely successful, they have made significant progress.

“Eradication is impossible this summer, because of the large number of nests,” he says. “Our technique for locating and treating the nests does seem to be working however.” 

Higgins says the underground ant nests are difficult to find because they leave no traces of their existence on the surface. He's been finding them by laying out slices of apple in a grid pattern.

“They don’t travel far in their search for food, so a large number of ants on a piece of apple indicates there is a nest within one metre,” he says.

Higgins says once a nest is found, approximately 10 litres of soil surrounding the nest is dug up and treated with a .025 per cent solution of Permethrin. The mixed soil is then poured back into the nest. Permethrin is used to treat lice on children's heads.

“The ants build lateral escape tunnels, so as soon as a shovel hits the ground, the queen runs away," he says. "The treated soil kills ants in the nest and traps the queens, giving them nowhere to go but back into the treated soil."

The process has been slow and difficult because of the large number of nests now in Naramata, he says. While the ants aren’t increasing their territory, the nests have become fragmented resulting in an increase in density.

“Where there was one nest last year, this year there are two or three,” he says.

Higgins says he is planning to hold an evening workshop for Naramata residents to show them how to deal with fire ants. He doesn't have a date yet.

The biologist doesn't know yet if he'll be back in the South Okanagan next year to continue the battle in the insects. He's waiting to hear back about provincial funding.

To contact the reporter for this story, email Steve Arstad at sarstad@infonews.ca or call 250-488-3065. To contact the editor, email mjones@infonews.ca or call 250-718-2724.