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Three Mediterranean recluse spiders were discovered in the Shapiro Undergraduate Library at the end of January. An email sent out to library staff Monday, a copy of which was obtained by The Daily, said the recluse spiders were found in a basement machine room in the UGLi by a pest management system.

University spokesperson Kim Broekhuizen wrote in an email to The Daily that the library “closed out of an abundance of caution.”

“Pest Management is working to treat the areas in the buildings where the spiders were found,” Broekhuizen said. 

Broekhuizen also confirmed that a small number of Mediterranean recluse spiders were found in the Stearns Building on North Campus. A sign posted in the building incorrectly stated that brown recluse spiders were found in the building, and this sign is being corrected to say Mediterranean recluse spiders, Broekhuizen wrote. Pest management is currently treating the area where the spiders were found.

The email sent to library staff says that a recluse spider’s bite can cause severe necrosis, or death of body tissue, in a small number of cases. Mediterranean recluse spider bites rarely lead to loxoscelism, a condition causing skin lesions. Reactions to Mediterranean recluse bites can be delayed by two to six hours, and the bite itself is painless.

“Bites are rare,” the email reads. “However, they can occur from contact, which usually happens when someone is looking for items in storerooms, attics, basements, or cluttered areas, or within cardboard boxes and makes contact with the spider.”

The announcement noted that recluse spiders have been found in the tunnels under campus buildings before, and that this is likely how they entered the UGLi. Pest management is continuing to monitor the situation, employing traps and pesticides within and near the tunnels, but no more spiders have been found since late January.

The email said that recluse spiders are, as their name suggests, naturally reclusive and would likely run away from a person rather than attack. 

For faculty working in the UGLi, the email said the best safety precautions include covering your skin when handling stored items, cardboard boxes, lumber and/or rocks. 

Library staff were also advised to store items in plastic and off the floor, or seal cardboard boxes with tape. 

The UGLi will reopen Tuesday for individual study by appointment only. Staff who are retrieving any items from storage are encouraged to exercise caution and report any Mediterranean recluse spider sightings. 

Correction: A previous version of this article said the spiders found at the Shapiro Undergraduate Library were brown recluse spiders. The spiders were Mediterranean recluse spiders. This story has also been updated to include information about recluse spiders in the Stearns Building on North Campus and more accurately reflect Broekhuizen’s statement about pest management in the library.

Daily Staff Reporter Paige Hodder can be reached at phodder@umich.edu

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