Sunday, September 30, 2012

Adventures in Spider Misidentification: Agelenopsis

Albertan Funnelweb Spider: Agelenopsis cf utahana (Chamberlin & Ivie, 1933) 
In Australia, a funnel-web spider is something to respect. Typically these are rather large spiders with large, forward-striking fangs that can deliver a good quantity of dangerous venom. Although the females tend to stick to their funnel webs, the males wander and often get into trouble. The most notorious of these, the Sydney Funnel-web Spider Atrax robustus O.P.Cambridge, 1877, exhibits all the characteristics you'd least like to find in a spider sharing your garden: they are large, aggressive, and their bite can kill you.
Alberta Funnel-wb aka Grass Spider: not very large, aggressive, or venomous
In Alberta we don't have any relatives of the Sydney Funnel-web, but we do have spiders in a very distantly related family, Agelenidae, that make funnel-webs and are called Funnel-web, Funnel-weaver, or Grass Spiders. If you have walked through a grassy field in the early morning and seen a funnel-like web covered in dew, then you have probably seen the home of an agelenid spider. Last week as my wife and I were sitting on our back porch enjoying an Indian Summer evening, we discovered we had our own resident funnel-weaver sitting right behind us. Mostly she lurked in her funnel within the door drain, but she'd quickly dash out for a picture when an insect was tossed on the web.
Striped carapace and body, long spinnerets, funnel web, and eye pattern = Agelenopsis
You can just see the long spinnerets sticking out behind the longitudinally striped body of the spider above and the funnel web (at the top of the post). Along with the eyes set in two down-curved rows, all of these characters indicate we have a species of Agelenopsis. We think this is Agelenopsis cf utahana (Chamberlin & Ivie, 1933) because it looks right and the Strickland Museum has numerous records for the species, and no other, from Alberta.
The eyes have it: two curved rows = Agelenopsis
I'm pretty sure this is an Agelenopsis, but I use cf - an abbreviation for the Latin word confer ('compare') - as a CYA on the species. Other species may occur here and the identity in this genus, as in many spiders, is best confirmed by examining the palps of the male. If you want to see some excellent photos of the male of A. utahana, and an amusing video of the kind of trouble a wandering spider can get into, visit Splendor Awaits. As you can see from Adrian's video, male funnel-web spiders in Alberta are nothing to be afraid of and probably would much rather not make our acquaintance.


  1. I never did find that spider after it scampered off!

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  3. There has been an ID update at BugGuide, and I'll be amending my post to suit.