Biochemical Soul Musings on Nature, Science, Evolution, Biology, and Education


Another Black Widow Where She Shouldn’t Be

Southern Black Widow tending her nest above my porch

Southern Black Widow tending her nest above my porch

I just got home and happened to look up into the corner of my porch today, when what do I see but a Northern Black Widow (Latrodectus variolus) tending her egg case above my steps.

I have seen hundreds of black widows at my house (see some really cool closeups in my previous post on black widows). Normally they are down low, barely above the ground, peeking out from leaves or tree roots. Occasionally I'll see them hanging beneath my porch steps. But this is the first time I've seen one elevated so high. My guess is that she is only roosting so high for the sake of her eggs.

Hanging up high instead of down low

Hanging up high instead of down low

Below is a cool video I took of a black widow I caught this summer.  As mentioned before, the widows I've seen in North Carolina are the Northern Back Widow (Latrodectus variolus), and not the Southern Black Widow (Latrodectus mactans), though it is my understanding that their neurotoxin venoms are equally dangerous. That being said, bites are extremely rare and deaths rarer. They are very unaggressive in my own experience and will instantly hide when approached. I usually just note their locations and leave them alone. This girl, however, is not long for this earth. Too close to my door, and I don't want the babies working their way inside. Plus, my wife is terrified that we have so many widows around to begin with. If it's any consolation to you insect/arachnid lovers, I am usually much kinder and appreciative of our six- and eight-legged cousins than most.

You can tell the species apart by the fact that Southern Black Widow has a complete abdominal hourglass, while Northern Black Widows have a "broken" hourglass (see the movie below and this previous post).

Also, if you like cool spider videos, check out this Golden Garden Spider video I took.

Northern Black Widow videos:

For your own edification, here is a bit about their venom from wikipedia:

The venom spreads rapidly throughout the body and acts by causing the release of the neurotransmitters acetylcholine, norepinephrine, and GABA.

And symptoms:

During the first 24 hours after a bite:

In some rare and extreme cases, severe complications can arise:

Symptoms that may be present at or near the wound:

Comments (5) Trackbacks (2)
  1. I’ve never seen one of those. I don’t know if they come up as far north as MD.

  2. I’d never seen one till coming to North Carolina. Had lots of Southern Black Widows in Arkansas.

    According to Wikipedia, the Northern Black Widow ranges all the way up into New York.

    But I don’t know how the hell things like this survive winter up there. I’m a warm-blooded mammal and I think that even I would die within a few weeks. :)

  3. Severe muscle pain? headache? fatigue? insomnia? vomiting? tearing up? Funny on how the symptoms of a black widow bite sound a lot like an episode of The Amazing Race.

    Nice videos and photos! I found one near my apartment and have some shots up at my site. Check em out if your so inclined.

    I’m glad I found your blog!

    • Dude! Those pictures you took are AMAZING!!

      Everyone who comes here should go see them, now!

      I’m glad you posted that – I’ve never seen the Western Black Widow species before. Perhaps I will when I (if I) move to San Diego.

      • Thanks for the compliments on the pics!

        Will you see the western black widow in SD? You most definitely will. You might glimpse the brown widow (Lat. geometricus) as well. The African arachnid made its first appearance here in SoCal about ten years ago and seems to rule the land surrounding my apartment a few months of the year. But they’re shy compared to the western black widow (Lat. hesperus) and it isn’t well reported how venomous their bite is.