Poisonous spider extends her web to GTA

Her abdomen is no bigger than the tip of a pinky finger, but her venom could kill a small child.

And now this fabled doyenne of death may be hanging out in a garage or park near you as the “northern” line of the species invades the Greater Toronto Area for the first time.

“I don’t want it to be a scare story ... the risk is very low to people,” says Antonia Guidotti, a Royal Ontario Museum entomologist and one of the province’s point people for identifying strange bug species.

“But I’m a mom. I have two children. So it doesn’t hurt to be aware that there is a very small potential that they could be around (you).”

Guidotti has confirmed two northern black widow finds in the GTA over the past year – one in a Mississauga garage and another in a Bolton-area cottage.

And if there are two latrodectus variolus about, there are certainly more, Guidotti says. Since widow “spiderlings” leave home by spinning a sail-like web and throwing themselves to the winds, they could land anywhere – even in the city.

Ontario sightings of the northern black widow have been confirmed over past decades in London, Grand Bend, along the Bruce Peninsula and on some Georgian Bay islands. And for some reason, Guidotti says, they’ve been especially common in Barrie.

Their presence in the GTA, however, does not send the odds of being bitten in these parts soaring, Guidotti assures.

“Their behaviour is such that we don’t come across them that much,” she says.

“They build their webs on the ground in dark areas outside, so you’re not likely to find them in your homes.”

Northern black widow females – the poisonous ones – can be recognized by an hourglass-shaped orange blaze on their abdomens. The widow uses its neurotoxin venom to subdue insect prey. But the bite can pack a human-sized wallop.

Aside from pronounced swelling around the puncture wound, the venom causes severe abdominal pain, sweating and muscle cramping.

“Now, small children, the elderly and people with compromised immune systems or who are weaker are always at higher risk with any kind of bite,” she says.

Anti-venom is available in this country, but is in very sparse supply, says Dr. Margaret Thompson, medical director of the Ontario Poison Centre. “There might be two vials of it in Canada.”

But Thompson says a network of zoos and poison centres across North America can ship supplies in when needed.

“Most of the calls we get about black widow (bites) come from critters that are imported into Canada rather than from the native ones,” says Thompson, whose centre treats about two widow attacks a year. “We most often get them from workers who are unpacking stuff that comes in from Mexico, for example.”