Following our creepy encounters with giant spider webs and bugs in orange and black, this week we continue our Halloween theme with a visit from another notorious and often misunderstood spider, the Mediterranean recluse. Less well known than its cousin, the brown recluse, this spider is a common resident in several government buildings in Washington, D.C. It is described as “troglophilic” or “cave loving” due to its habit of dwelling in damp, dark, underground structures such as the basements, mechanical rooms, and steam tunnels beneath buildings and streets. Washington is not the only home for the Mediterranean recluse. As its name implies, Europe and Northern Africa are the native range of this species. However, like many recluse spiders, this one travels well with man and now Australia, Asia, North America, and several islands in the Atlantic and Pacific have their own populations of this spider.
Discoveries of Mediterranean recluses have increased in recent years in the nation’s capitol. The surge in detections in government buildings may be due to the rapid turnover of government personnel and accompanying relocation of files and furniture. Recluse spiders are excellent hitchhikers and moving equipment, furnishings, and records provides a convenient mode to travel from one building to the next. Remember recluse spiders are predators. There is no need to worry about them showing up at the vending machine or cafeteria looking for snacks. Their usual fare includes small six-legged denizens of the nether realm that scurry about basements and crawlspaces. Concerns exist about health risks associated with recluse spiders due to the widespread fear of flesh-destroying toxins found in their venom. Most spider experts agree that bites of recluse spiders have the potential to cause tissues damage. However, people rarely experience severe tissue damage when bitten by a recluse. Only in very isolated cases do potentially fatal complications arise. According to experts “typical symptoms” tend to be minor. Two facts should help alleviate concerns regarding bites by Mediterranean recluse spiders. First, they usually occupy subterranean habitats and storage rooms where encounters with humans are rare. In addition, despite a somewhat scary appearance, recluse spiders are very shy and would much rather avoid a human than attack and bite one. In fact, scientists found a complete absence of reports of regular workers and occupants suffering harm or even encountering recluse spiders in infested buildings in Washington, D.C. On this Halloween the only ones likely to encounter a Mediterranean recluse spider in the nation’s capitol will be the ghosts of politicians and bureaucrats haunting the hallowed halls of our government’s basements.
We thank Dr. Nancy Breisch for providing inspiration and allowing us to photograph her delightful Mediterranean recluse spiders for this episode of Bug of the Week. The article “ The Mediterranean recluse spider; Loxosceles rufescens (Dufour): An abundant but cryptic inhabitant in deep infrastructure in Washington, D.C. area (Arachnida: Araneae: Sicariidae)” by Albert Greene, Nancy Breisch, Thomas Boardman, Benedict Pagac, Edward Kunickis, Randall Howes, and Paul Brown was used as a reference for this episode. For more information of recluse spiders, please visit the following web site.