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Brown Recluse (Loxosceles reclusa)


Detailing the physical features, habits, territorial reach and other identifying qualities of the Brown Recluse.


 Updated: 2/9/2018; Authored By Staff Writer; Content ¬©www.InsectIdentification.org



  Brown Recluse  
Picture of Violin-Spider-Brown-Recluse
Picture of Violin-Spider-Brown-Recluse Picture of Violin-Spider-Brown-ReclusePicture of Violin-Spider-Brown-Recluse


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.
Basic Information
Common Name: Brown Recluse
Other Name(s): Violin Spider, Fiddle Back Spider, Fiddleback
Scientific Name: Loxosceles reclusa
Category: Spider


General Identification
Size (Adult; Length): 7mm to 10mm (0.27in to 0.39in)
Colorwheel Graphic
Identifying Colors: orange; yellow; brown; gray
Additional Descriptors: violin, shiny, biting, venomous, poisonous, toxic




Taxonomic Hierarchy
Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Sicariidae
Genus: Loxosceles
Species: reclusa


Spider Anatomy (Typical)
Graphic showing basic parts of spider anatomy
1
Legs: Spiders have four pairs of legs and these are attached to the cephalothorax.
2
Pedipalps: Small appendages near the mouth used as taste and smell organs.
3
Cephalothorax: Contains eyes, head, mouthparts, and legs.
4
Abdomen: Contains various organs related to digestion, reproduction, and web-making.
5
Spinnerets: Used in the production of spider silk for fashioning webs or catching prey.
NOTE: Unlike insects, spiders have both an endoskeleton (internal) and exoskeleton (external).


Territorial Reach (A-to-Z)
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed below as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections below indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Connecticut
Delware
Florida
Georgia
Hawaii
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
Montana
Nebraska
Nevada
New Hampshire
New Jersey
New Mexico
New York
North Carolina
North Dakota
Ohio
Oklahoma
Oregon
Pennsylvania
Rhode Island
South Carolina
South Dakota
Tennessee
Texas
Utah
Vermont
Virginia
Washington
West Virginia
Wisconsin
Wyoming
Canadian National Flag Graphic
Alberta
British Columbia
Manitoba
New Brunswick
Newfoundland and Labrador
Nova Scotia
Ontario
Prince Edward Island
Quebec
Saskatchewan
Mexican National Flag Graphic
Mexico


Territorial Area Map (Visual Reference Guide)
The map below showcases (in red) the states and territories of North America where the Brown Recluse may be found (but is not limited to). This sort of data can be useful in seeing concentrations of a particular species over the continent as well as revealing possible migratory patterns over a species' given lifespan. Some species are naturally confined by environment, weather, mating habits, food resources and the like while others see widespread expansion across most, or all, of North America.
Alaska  
Hawaii  
Prince Edward Is.  
State of Alabama graphic
State of Arizona graphic
State of Arkansas graphic
State of California graphic
State of Colorado graphic
State of Delware graphic
State of Florida graphic
State of Georgia graphic
State of Idaho graphic
State of Illinois graphic
State of Indiana graphic
State of Iowa graphic
State of Kansas graphic
State of Kentucky graphic
State of Louisiana graphic
State of Maine graphic
State of Maryland graphic
State of Michigan graphic
State of Minnesota graphic
State of Mississippi graphic
State of Missouri graphic
State of Montana graphic
State of Nebraska graphic
State of Nevada graphic
State of New England graphic
State of New Jersey graphic
State of New Mexico graphic
State of New York graphic
State of North Carolina graphic
State of North Dakota graphic
State of Ohio graphic
State of Oklahoma graphic
State of Oregon graphic
State of Pennsylvania graphic
State of South Carolina graphic
State of South Dakota graphic
State of Tennessee graphic
State of Texas graphic
State of Utah graphic
State of Virginia graphic
State of Washington graphic
State of West Virginia graphic
State of Wisconsin graphic
State of Wyoming graphic
Canadian territory of Alberta graphic
Canadian territory of British Columbia graphic
Canadian territory of Manitoba graphic
Canadian territory of New Brunswick graphic
Canadian territory of Newfoundland and Labrador graphic
Canadian territory of Ontario graphic
Canadian territory of Quebec graphic
Canadian territory of Saskatchewan graphic
Territory map graphic of the country of Mexico
Contiguous United States shape map layer graphic


Images Gallery for the Brown Recluse
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