Brown Recluse (Loxosceles reclusa)
Detailing the physical features, habits, territorial reach and other identifying qualities of the Brown Recluse.
Updated: 6/11/2018; Authored By Staff Writer; Content ©www.InsectIdentification.org
The sight of a Brown Recluse causes more anxiety in people than most spiders for good reason.
The Brown Recluse spider, also known as the Violin Spider or Fiddleback Spider, is generally found throughout the American South and west to California. The reach, or range, of this spider is stable and it is unlikely to be found outside of those states listed below. A similar-looking relative, the Desert Recluse spider, is more common in the drier western U.S. and is commonly mistaken for the Brown Recluse.
Identifying features of the Brown Recluse spider include a brown-to-gray abdomen, lighter coloring on the legs, and an orange-to-yellow cephalothorax. The area at the head and eyes has what appears to be violin-shaped birthmark on top of it (see photo). The round bottom of the 'violin' sits over the eyes, and the skinny neck of the 'violin' points back toward the abdomen. Every Brown Recluse has that violin-shaped marking, but some people believe they see it on other, harmless spiders causing unnecessary confusion and panic. For this reason, specialists recommend checking the eye pattern (see second photo) of the spider to be more certain that it is an actual Brown Recluse. The six eyes are in tight pairs, with one pair in the front center of the face and the other two pairs flanking the sides.
These spiders generally inhabit loose piles of debris outside. If indoors, they may be found lying on or inside furniture as well as within undisturbed clothing. Many bite victims put on clothing that was left on the floor, and are bitten by the frightened spider hiding inside. This spider is not naturally aggressive and does not seek out human victims. A young family in 2001 living in Lenexa, Kansas had no issues with the arachnid during the 5 years they lived with an infestation. Scientists from the University of California helped them trap, kill and collect over 2,000 Brown Recluse spiders during a 6 month period there.
The caution regarding this spider comes from its toxic venom. Brown Recluse venom is known to cause necrosis in human tissue. A hemotoxin present in the venom can destroy the tissue surrounding a bite. Infection can then set in and cause even more damage to tissues and possibly spread to organs. The wound develops a crusty-like appearance and texture that becomes surrounded by patches of redness and irritation. Though this crust eventually falls off, it leaves behind a deep, crater-like shape which may not completely heal for a period of months.
The good news is that over half of the known Brown Recluse spider bites on record caused no reaction in their victims and the bites healed nicely on their own. Other victims reacted only mildly with some redness and pain that developed over a few hours. Some perceived spider bites were actually other, already-present infections (like Staph) that were misdiagnosed by the victim. An ELISA-test (scientific test that analyzes the proteins in substance) can confirm if venom belongs to a Brown Recluse, but unfortunately, this test is a lab-based test not available at doctor's offices.
If one suspects he/she has been bitten by a Brown Recluse spider, effort should be made to capture the spider in a jar or bottle for proper identification. Try to avoid destroying important identifying features by head. (Bug sprays exist that kill spiders chemically, keeping the head intact). Immediately treat a bite by following the University of California - Riverside's suggestions for simple first aid (RICE): Rest, Ice the area, add Compression and Elevate the appendage if possible. Medical attention is strongly recommended if a Brown Recluse bite is confirmed especially if symptoms of pain and inflammation persist or increase. Every human body reacts differently. A medical professional can help relieve symptoms, monitor responses to the venom, and prevent further complications.