Ant Mimic Sac Spider - castianeria longipalpa

I've only been able to get as far as determining that this is in the family Gnaphosidae or Ground Spiders… otherwise I haven't been able to find a satisfactory match. The closest I've come is Callilepis Pluto, but I'm not convinced that the arrangement of the eyes on this spider is quite right, nor does the abdomen look exactly right either.

There were quite a few of these running around where I was - the were fast moving, roaming spiders without any apparent web. They liked to run under my shoe to hide if I stopped walking. When I'd lift my shoe they'd remain motionless for a small period of time - enough to snap a photo.

Update: BugGuide.net comes through. Someone recognized her right away. Looks to me to be an adult female Ant Mimic Sac Spider

comments (5)

Ferdy Christant

Lion

There's a close match on the bottom of this page...

http://www.spiderzrule.com/ground.htm

..but no exact species is mentioned. This one, however, looks quite similar and does have a species name:

http://bugguide.net/node/view/211174

What do you think? Posted 10 years ago
1. morpheme
  
  Lion
  
  So hard to say.. that one seems a lot hairier than mine (but that could just mean mine is a juvenile). I've submitted it to bugguide.net to see if any of their experts can say. They were so common where I was at I never figured they'd be so difficult to name, but there seem to be a good number of red/black ground spiders that look rather similar.
  
  This one was my best guess - http://bugguide.net/node/view/696164/bgimage Posted 10 years ago, modified 10 years ago
2. 1. Ferdy Christant
    
    Lion
    
    Really tough one indeed. I do notice that on the abdomen, yours has a pattern that somewhat looks like bands. Posted 10 years ago
  2. 1. morpheme
      
      Lion
      
      Yeah BugGuide - someone came up with it right away! castianeria longipalpa Posted 10 years ago
    2. 1. Ferdy Christant
        
        Lion
        
        That's a very useful site indeed, particularly for US species. Congrats on a really cool species intro. Posted 10 years ago

The Antmimic Spider

This spider often mimics carpenter ants by slowly waving its front pair of legs in the air as if they were antennae. It will also slowly “nod” its abdomen up and down just like the ants do.

This is a very distinctive spider. Abdomen is an elongated oval; usually brown, black, or dark red, and with four or more transverse bands of white or yellow hairs. Carapace is pear-shaped; base color is black, brown, or dark red, but usually covered in white or yellow hairs.

Info 1 0

Similar species: Spiders

Species identified by Ferdy Christant