Recent News – Black Widow spider

Northern Black Widow by cotinis at Flickr, used under Creative Commons license

Northern Black Widow by cotinis at Flickr, used under a Creative Commons license

A few days ago, Dan forwarded me an article from the Toronto Star. In case the link goes dead (as sometimes happens with online news articles) or you don’t want to click through, here’s a summary:

On July 28, a senior was working in her garden west of Toronto when she was bitten on her hand by a spider. She brushed the spider off, but very rapidly started suffering symptoms – excessive sweating, blurred vision, loss of muscular control. Her hand swelled up, and she was barely able to make it into the house to call her daughter, who in turn called an ambulance. By the time paramedics arrived, she was nearly paralyzed. After two weeks in the hospital, she’s regained use of most of her body, though her legs below the knees continue to lack feeling and she can’t yet walk.

The spider, although never found, was identified by its description and symptoms as a black widow. I suspect most Ontarians associate black widows with the arid southwest, such as Arizona, and would be surprised to hear of one in Ontario. They would be even more shocked, I bet, to learn that Ontario actually has a native species of black widow, the Northern Black Widow, Latrodectus variolus. Southern Black Widow spiders, L. mactans, do occasionally show up in Ontario in shipments of produce coming from these regions, but are extremely uncommon.

I had no idea that we had black widows in Ontario. Suddenly I feel less comfortable about using public outhouses… Generally, though, Northern Black Widows are of little concern. They tend to build very large, noticeable three-dimensional webs, usually in corners or crevices such as rotten stumps or stone walls. Unless you’re rooting around in or beside the web for some reason, you probably have little to worry about from these spiders, despite the strength of their venom. The dramatic symptoms of the woman in the news story are unusual, too, and most likely to occur in seniors, children, and individuals with venom allergies (eg., bee stings).

The Northern Black Widow is one of five widow spiders in North America, three of which are black (the other two are red and brown). Of the three blacks, it’s the most distinct, having a broken hourglass (as shown in the photo above). It ranges from Florida right up to southern Ontario. The Southern Black Widow actually makes it as far north as southern New York, as well, surprisingly. So much for being a spider of the arid southwest. A Western Black Widow, L. hesperus, ranges along the west coast from southern BC southward, and looks similar to the Southern.

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9 responses to “Recent News – Black Widow spider

  1. I too noted this story with interest having seen Black Widow spiders in Mexico. Thanks for taking the time to share your research about the Nothern Black Widow.

  2. Like my spider phobia wasn’t already bad enough! THANKS A LOT, SEAB!!!

  3. I’ve always been suspicious of outhouses too! I suppose we can expect more of there sorts of critters when global warming takes hold.

  4. Nightmares! Living in New Mexico, I have come so close to getting bitten several times. They love, love, wood piles. I always wore gloves when bringing wood into the house until after the first big freeze.

    • That’s good to note! I think they’re very uncommon up here, fortunately; despite having had a wood stove my entire life growing up, I never happened to encounter one in the wood piles, or elsewhere for that matter.

  5. Pingback: American Animals That Will Kill You - Slapped Ham

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