Wafer Lid Trapdoor Spider

Friend or foe?
April 19, 2010
I found this spider in my friends pool. The match book should provide a good estimate as to its size.
Aaron Grimes
Marin County, California

Wafer Lid Trapdoor Spider

Hi Aaron,
This looks to us like a Trapdoor Spider, probably a Wafer Lid Trapdoor Spider in the genus Promyrmekiaphila which BugGuide reports from California.  It looks like a male, and male Trapdoor Spiders often drown in swimming pools while searching for a mate.  Trapdoor Spiders are harmless to humans and pets.

Cork Lid Trapdoor Spider
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BugMan aka Daniel Marlos has been identifying bugs since 1999. WhatsThatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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