Subject: Adult spider in a cocoon
Location: Mesa, AZ
November 6, 2012 4:55 pm
Cocoon measures approx. 1.5 inches across. Found attached to a piece of wood in Mesa, AZ. Spider appears to be alive but dormant. The cocoon was very hard to tear open. I was surprised to see an adult spider inside. I can send bigger pics if need be. Any idea what it is?
Signature: Nathan

Dormant Female Giant Crab Spider

Hi Nathan,
This sure looks like a female Giant Crab Spider or Huntsman Spider, Olios peninsulanus, when compared to this image on BugGuide, though she may be another member in the same genus.  We are very curious about the circumstances of this sighting.  We will contact Eric Eaton to see if he knows anything about Giant Crab Spiders going dormant.

Eric Eaton Responds
I am guessing that this is how they overwinter.

Wow, what a cool spider. My kids are home schooled so we are always on the hunt for something to get them excited. This spider sure got them excited. Thanks for the ID!
“These spiders generally settle into one place only at egg-laying time. Females produce large egg bags that they hide in and guard.”

Hi again Nathan,
Thanks for the additional link.  We aren’t certain of the species, but we are confident with the genus
Olios identification.

Location: Arizona

2 Responses to Hibernating female Giant Crab Spider, or is that an egg bag?

  1. Joshua says:

    I captured one running around my house.
    Built it a nice little home while winter passes. She seems to enjoy flys a lot.
    About 3 weeks ago she started to make a sack out of this web like material. 3 days of working and she sealed her self inside the sack. I’m wondering how long she will be in there.
    I’m from gold canyon arizona. About 15-20 minutes from MESA Arizona.

    • bugman says:

      If she is hibernating, she will likely emerge when the weather is more suitable. If she is guarding eggs, she will probably emerge when the spiderlings are ready to disperse. Either way, we suspect not more than a few months.

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