Female California Trapdoor Spider

Subject: Chillin’ California Trap Door Spider Beauty
Location: San Pedro, CA
May 22, 2013 7:09 pm
Look who I found! A big beauty in San Pedro in April, 2013. My friend called me and said she’d found a pipe in her bare-earth backyard. She then called back and said it was a tube. I came by to investigate. We gently opened a few trap doors and this beauty clung to the top of her trap door, so I gently removed her. After a weak threat display, I picked her up, took photos, and gently placed her back, thanking her and closing her trap door.
Signature: Darlene King

Female California Trapdoor Spider
Female California Trapdoor Spider

Dear Darlene,
Thank you so much for sending us this exciting posting.  Though we have numerous photos of male California Trapdoor Spiders,
Bothriocyrtum californicum, photos of females are noticeable absent on our site.  We believe your identification is correct because of the resemblance to this California Trapdoor Spider on BugGuide.  Up until recently, the information page on BugGuide has been quite spare, but this marvelous addition is quite fascinating: “According to Guinness World Records, as of 2009, this is the strongest spider. It has been able to resist a force 38 times its own weight when defending its trapdoor. This equates to a man trying to hold a door closed while it is being pulled on the other side by a small jet plane!(1) Unfortunately, the Guinness book doesn’t mention if it’s the strongest North American spider or if it’s the strongest in the world. Also, one thing to think about is whether or not every spider’s strength has been measured. I guess one can safely say that the information is flawed in that aspect, but it still asserts the fact that these spiders ARE very strong.”Because of habitat loss in urban areas, California Trapdoor Spiders are becoming scarcer in many parts of their range, including Los Angeles, where the preservation of more open space might be a necessity for their survival.  Our own nearly 36 acre natural gem, Elyria Canyon Park, is likely a contributing factor in the presence of California Trapdoor Spiders where males frequently fall into swimming pools at the start of rainy season.  Me must say we are quite impressed with your handling of this large but benign spider.  Trapdoor Spiders wait patiently in their lairs to pounce upon any small arthropod or possibly even small vertebrate that crosses their perimeter. 

Female California Trapdoor Spider
Female California Trapdoor Spider

We like the use of the dogs for scale.

Almost as big as a dog:  Female California Trapdoor Spider
Almost as big as a dog: Female California Trapdoor Spider


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