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Entomology (Study of Bugs)/Common brown/black spider in San Diego?


Brown Spider in San Diego, CA
Brown Spider in San Di  

Brown Spider in San Diego, CA
Brown Spider in San Di  
This must be breeding season for spiders, they are everywhere right now.  Spider located in bathroom sink around 10pm October1, in San Diego, CA (about 5 miles east of beach).  It had an even gait trying to crawl out of sink in circles.  Froze when I approached it.  About the size of a quarter.  Desert recluse?  House spider? Brown widow?  I have seen Brown widow sacs outside the last 2 years, and 100% sure have seen black widows, but not sure about this guy.  A similarly colored one dropped down in front of my computer screen the other night (hence, I'm Miss Muffet!) but not sure if it's the same species.  Didn't have time to snap a pic of that one!

Dear Ms. Muffet:

Thank you for both the nice, clear images, and the thorough description of its behavior.  You obviously have done some homework, and have a delightful sense of humor!

Near as I can tell, this is an immature specimen of the "False Black Widow," Steatoda grossa , a very common spider on the west coast.  Here's more about it:

Thanks again for sharing your experience.  Love your personality and hope our paths cross again.


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Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

Awards and Honors
One of the top 50 experts in all categories for, 2009.

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Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

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