What kind of spider is this?

Asked May 10, 2016, 2:00 PM EDT

I live in Tennessee and found this huge spider under my house. It resembles a mouse spider almost perfectly.... But obviously it can't be.

Wilson County Tennessee

3 Responses

Thank you for your question. The photographs are pretty dark, but I believe this is Ummidia audouini, the southern trapdoor spider. This spider belongs to the suborder Mygalomorphae. They are considered one of the primitive groups of spiders and include tarantulas, funnel-web and trapdoor spiders. This spider can be fairly common, but because it spends a lot of time in its burrow, and is nocturnal, it's not seen often. Most of the time it is encountered following a heavy rain that may flood its burrow or when people dig through its burrow while working in their garden or digging a trench for a water line, for example. Their burrow is concealed by a trap door, constructed with silk, soil and debris, which the spider holds closed with the tips of its fangs. At night, it will hold the trapdoor slightly open and wait for prey to wander by. It then rushes out grabs the prey and pulls it back into its burrow. Their bite is not considered a significant health risk to humans, and has been compared in severity to a wasp sting.

Here's a couple of links for more information on this species:

Arthropod Museum, Dept. of Entomology, University of Arkansas:
http://www.uark.edu/ua/arthmuse/trapdoor.html

North Carolina Museum of Natural Sciences:
https://ncmns.wordpress.com/2015/07/30/soil-sidekicks-trapdoor-spider/

By the way, this species does look similar to the mouse spider, genus Missulena, which is native to Australia. Missulena is also a Mygalomorph, but in a different family than Ummidia.

Hope this answers your question, and thank you for using Ask an Expert.

Jim

Thank you so much, I let it go back into a safer environment. I am terrified of spiders so it really spooked me to see one so large. Thank you again!

You're welcome, anytime. Most species we have in North America are rather delicate, but, you're right, this one is a very formidable looking spider.

Jim