Loxosceles rufescens (Dufour, 1820), the Mediterranean recluse spider
Last month, I found this spider in Seitz Hall on the campus of Virginia Tech where we house the Virginia Tech Insect Collection. At first glance, I thought it was a Brown recluse spider (Loxosceles reclusa Gertsch & Mulaik, 1940), but sent the specimen to Matt Bertone at North Carolina State University, who determined it was the Mediterranean recluse.
The Arthropod Museum in the Department of Entomology at the University of Arkansas has a nice article about the two species and how to tell them apart. The Mediterranean recluse is an introduced spider with origins in the Mediterranean region, but it is well established in many places. Another introduced species of arthropod from the Mediterranean region is the fleet-footed House centipede Scutigera coleoptrata (Linnaeus, 1758). As both are predators, I imagine them battling it out for the delectable cockroaches and silverfish prey running around.
Scutigera coleoptrata (Linnaeus, 1758), the House centipede