Brown Recluse, Fiddleback Spider, Violin Spider
Loxosceles reclusa
Sicariidae (Six-eyed Sicariid Spiders), Order Araneae
Physical Description
A medium-sized spider with a smooth, non-hairy appearance to the naked eye. It features a distinct cephalothorax (front body segment) that is slightly flattened and an oval-shaped, uniformly colored abdomen. The most famous anatomical feature is the dark violin-shaped marking on the top of the cephalothorax.
Size Estimate
Body length typically ranges from 6 to 20 mm (1/4 to 3/4 inch). With legs extended, they are approximately the size of a U.S. quarter (about 1 to 1.5 inches in diameter).
Coloration & Markings
Light to medium brown, though color can range from whitish to dark gray or blackish-brown. The abdomen is uniform in color without spots or stripes. The key marking is a dark brown, violin-shaped silhouette on the cephalothorax, with the 'neck' of the violin pointing toward the abdomen.
Web Type
Irregular, small, off-white to grayish 'tangle' webs. These are not used for catching prey but serve as retreats. They are typically hidden in dark, undisturbed areas like woodpiles, sheds, or behind baseboards.
Eye Arrangement
Distinguished by having only six eyes arranged in three pairs (dyads) in a semi-circle across the front of the cephalothorax, unlike most spiders which have eight eyes.
Leg Characteristics
Long, thin, and uniformly colored legs without any spines or banding. The legs are covered in very fine hairs that are difficult to see without magnification. They are typically held in a somewhat flattened, sprawling posture.
Venom & Safety Information
Venom Information
Possesses a potent cytotoxic (cell-destroying) venom containing the enzyme sphingomyelinase D. This can cause necrosis (tissue death) at the bite site, though many bites result in only minor swelling and redness.
Medical Significance
Medically significant. Bites may be initially painless but can develop into a necrotic ulcer over several days. Systemic reactions (loxoscelism) are rare but serious. Seek medical attention if a bite is suspected, especially if a 'bullseye' pattern or blister forms.
Safety Recommendations
Shake out shoes and clothing stored in dark areas before wearing. Use gloves when moving boxes or woodpiles. To relocate, use a jar and stiff paper to capture and move it outdoors far from the foundation.
Habitat & Behavior
Habitat & Range
Primarily found in the Central and Midwestern United States. They prefer dark, dry, undisturbed locations such as attics, basements, crawl spaces, closets, and inside cardboard boxes or stored clothing.
Behavior & Temperament
Reclusive and non-aggressive. They are nocturnal hunters that leave their retreats at night to search for food. They only bite when provoked or pressed against skin, such as when trapped in clothing or bedding.
Diet & Prey
Opportunistic hunters that feed on a variety of small insects like silverfish, crickets, and cockroaches. Unlike orb-weavers, they actively hunt and subdue prey rather than relying on a web to trap it.
Seasonal Activity
Active year-round in temperature-controlled homes, but peak activity and mating typically occur from early spring through summer.
Description
The Brown Recluse is one of the few medically significant spiders in North America. Known for its 'violin' marking and six eyes, it is a shy creature that avoids human contact. Despite its fearsome reputation, it plays a vital role in controlling indoor pest populations.
Key Features
Uniformly colored abdomen (no patterns), violin-shaped mark on the cephalothorax, six eyes in three pairs, and legs without thick spines.
Similar Species
Often confused with Wolf Spiders (Lycosidae), House Spiders (Tegenaria), and Cellar Spiders (Pholcidae). These other spiders usually have eight eyes and distinctive patterns on their abdomens or spines on their legs.
Life Cycle
Females produce 1-5 egg sacs containing roughly 50 eggs each. Spiderlings reach maturity in about a year. They are notably long-lived for small spiders, often surviving 2 to 4 years in optimal conditions.
Ecological Importance
Acts as an effective natural pest controller in indoor environments, preying on disease-carrying insects and common household pests.
Conservation Status
Not listed. Populations are stable and common within their endemic range.
Interesting Facts
The Brown Recluse can go for many months without food or water. Despite being feared, many people live in infested homes for years without ever being bitten due to the spider's extremely shy nature.
Photography Tips
A clear top-down shot of the 'violin' mark and a macro shot of the eye arrangement (the three pairs) are the best ways to confirm identification. Ensure good lighting to see the smooth texture of the legs.
Identified: 2026-06-15T09:50:47.538014