Brown Recluse Spider, Fiddleback Spider, Violin Spider
Loxosceles reclusa
Sicariidae (Six-eyed Sand Spiders), Order Araneae
Physical Description
A medium-sized spider with a relatively flat cephalothorax and an oval-shaped, velvety abdomen. It has a smooth, non-spiny leg texture and fine hairs. The most distinctive feature is the darker, violin-shaped mark on the cephalothorax.
Size Estimate
Body length 6-20 mm; leg span approx 25-38 mm (about the size of a U.S. quarter). This specimen appears to be an adult.
Coloration & Markings
Uniformly light brown to tan body with no stripes or bands on the legs. Features a dark brown 'violin' or 'fiddle' marking on the cephalothorax, with the neck of the violin pointing toward the abdomen.
Web Type
Tangle/Sheet web. They build irregular, grayish, sticky webs in undisturbed, dark locations used as retreats rather than for snaring prey.
Eye Arrangement
Six eyes arranged in three pairs (dyads) in a semi-circle: one median pair and two lateral pairs. Most spiders have eight eyes.
Leg Characteristics
Long, slender legs held at a somewhat flat angle. They lack thick spines but are covered in fine hairs. Legs are uniformly colored without banding or contrasting spots.
Venom & Safety Information
Venom Information
Cytotoxic (necrotic) venom containing the enzyme sphingomyelinase D, which breaks down cell membranes and can cause localized tissue death.
Medical Significance
Medically significant. While 90% of bites heal without complication, some cause necrotic skin lesions (loxoscelism). Systemic reactions are rare but serious. Seek medical attention if a bite is suspected.
Safety Recommendations
Shake out clothing and shoes left on the floor. Wear gloves when moving boxes in storage. Use glue traps for monitoring. If bitten, clean the area, apply ice, and consult a doctor.
Habitat & Behavior
Habitat & Range
Found primarily in the Central and Southern United States. They prefer dark, dry, undisturbed areas such as attics, basements, closets, and behind furniture.
Behavior & Temperament
Reclusive, nocturnal hunters. They are non-aggressive and typically only bite when pressed against skin (e.g., inside clothing or bedding). They prefer to run rather than fight.
Diet & Prey
Generalist predators feeding on soft-bodied insects like silverfish, crickets, and cockroaches. They are active hunters that leave their webs at night to forage.
Seasonal Activity
Active year-round indoors, but peak activity and human encounters usually occur from spring through early autumn.
Description
The Brown Recluse is a modest-looking but medically significant spider known for its tendency to hide in the shadows of human dwellings. It is easily identified by its unique eye arrangement and the fiddle-shaped marking on its head.
Key Features
Violin-shaped marking on cephalothorax, six eyes in three pairs, uniformly colored legs with no spines/bands.
Similar Species
Cellar spiders (Pholcidae) have much longer, thinner legs; Southern House Spiders (Kukulcania hibernalis) are larger and lack the specific eye pattern; Wolf Spiders (Lycosidae) have thick spines on legs and different eye patterns.
Life Cycle
Females produce 1-5 egg sacs containing about 50 eggs each. They can live 1-2 years and are highly resilient, capable of surviving months without food or water.
Ecological Importance
Provides significant natural pest control within homes and structures by consuming common household pests like silverfish and cockroaches.
Conservation Status
Not listed (Stable). They thrive in human-altered environments.
Interesting Facts
They are famously hardy and can survive extreme temperatures and long periods of starvation. They are also known to scavenge on dead insects, which is rare for spiders.
Photography Tips
A clear macro shot of the eyes (dyad arrangement) and the 'violin' mark on the cephalothorax is essential for positive identification.
Identified: 2026-06-22T16:36:18.196829