Brown Recluse, Violin Spider, Fiddleback Spider
Loxosceles reclusa
Sicariidae (Six-eyed Sand Spiders and Recluse Spiders), Order Araneae
Physical Description
A medium-sized spider with a relatively flat cephalothorax and an oval-shaped abdomen. The body is covered in fine, short hairs giving it a velvety texture. They lack heavy spines on the legs and instead have fine hairs.
Size Estimate
Body length typically ranges from 6 to 20 mm (1/4 to 3/4 inch). With legs extended, the total diameter is approximately the size of a U.S. quarter (around 25-38 mm).
Coloration & Markings
Usually tan to dark brown or grayish-yellow. The most diagnostic feature is a dark, violin-shaped mark on the cephalothorax, with the neck of the violin pointing toward the abdomen. The abdomen is uniformly colored with no spots or stripes.
Web Type
Irregular, sticky, off-white tangle webs. These are not used for catching prey but as a retreat. They are typically built in dark, undisturbed corners or under boxes.
Eye Arrangement
Six eyes arranged in three pairs (dyads) in a semi-circle: one median pair and two lateral pairs. This distinguishes them from most other spiders which have eight eyes.
Leg Characteristics
The legs are long, slender, and uniformly colored without banding. They have a smooth appearance since they lack the thick bristles or spines found on wolf spiders or grass spiders.
Venom & Safety Information
Venom Information
Contains a necrotic enzyme called sphingomyelinase D. The venom is cytotoxic, meaning it can cause tissue death (necrosis) at the site of the bite.
Medical Significance
Medically significant. While many bites result only in minor swelling, some develop into necrotic lesions. Very rarely, systemic reactions (loxoscelism) occur, involving fever and chills. Seek medical attention if a bite is suspected.
Safety Recommendations
Shake out shoes and clothing left on the floor. Wear gloves when moving old boxes. If found, relocate using a jar and stiff paper. Do not handle directly.
Habitat & Behavior
Habitat & Range
Primarily found in the Central and Midwestern United States. They prefer dark, dry, undisturbed areas like basements, attics, cardboard boxes, closets, and woodpiles.
Behavior & Temperament
Reclusive and shy by nature. They are nocturnal hunters that roam for prey rather than waiting in webs. They generally only bite when pressed against skin, such as when trapped in clothing or bedding.
Diet & Prey
Generalist predators that feed on variety of small insects like silverfish, crickets, and cockroaches. They actively hunt at night and use their venom to quickly subdue prey.
Seasonal Activity
Active year-round indoors, but most sightings occur between March and October when males roam in search of mates.
Description
An infamous yet misunderstood inhabitant of the American Midwest. The Brown Recluse is a master of stealth, preferring the quietest corners of human dwellings where it provides natural pest control against household insects.
Key Features
Violin-shaped marking on the cephalothorax, six eyes in three pairs, uniformly colored abdomen, and lack of leg spines.
Similar Species
Often confused with Tegenaria species (Hobo spiders) or Grass spiders, which have eight eyes and distinctive abdominal patterns or visible spinnerets.
Life Cycle
Females produce 1-5 egg sacs containing about 50 eggs each. They can live for 1 to 2 years. They are remarkably resilient and can survive long periods without food or water.
Ecological Importance
Acts as a primary predator of common indoor pests, helping to regulate populations of insects that might otherwise infest homes.
Conservation Status
Not listed on IUCN Red List; populations are stable and common throughout their native range.
Interesting Facts
The Brown Recluse can go for several months without food. They are also known for their 'clumsy' walking style compared to the precision of other spiders.
Photography Tips
A macro shot focusing on the top of the cephalothorax is essential to see the violin mark and the three pairs of eyes.
Identified: 2026-05-18T12:42:32.032901