Brown Recluse Spider, Fiddle-back Spider, Violin Spider
Loxosceles reclusa
Sicariidae (Six-Eyed Sicariid Spiders), Order Araneae
Physical Description
The brown recluse has a uniform, violin-shaped marking on its cephalothorax, with the neck of the violin pointing toward the rear of the abdomen. The body is finely covered with short hairs and lacks striking patterns on the abdomen, which is oblong and uniformly tan to dark brown.
Size Estimate
Body length is typically 6 to 20 millimeters (0.24 to 0.79 inches), with a leg span ranging from 20 to 30 millimeters (0.79 to 1.18 inches). This appears to be an adult specimen.
Coloration & Markings
Colors range from yellowish-tan to dark brown. The defining marking is the dark violin shape on the dorsal cephalothorax. The abdomen is uniformly colored without bands, stripes, or mottling.
Web Type
Irregular, loose, sticky retreat web usually constructed in dark, undisturbed places like woodpiles, under rocks, or inside wall voids, rather than a symmetrical orb or sheet web.
Eye Arrangement
Six eyes arranged in three distinct pairs (dyads): one pair in front and a pair on each side. This is a key diagnostic feature for the family Sicariidae, as most spiders possess eight eyes.
Leg Characteristics
Long, thin, delicate legs of a uniform color lacking prominent spines, banding, or stripes. They are often held out flat or slightly curved in a typical resting posture.
Venom & Safety Information
Venom Information
Contains a potent dermonecrotic venom (specifically sphingomyelinase D) which can cause localized tissue destruction, necrosis, and slow-healing wounds in humans.
Medical Significance
Medically significant. Most bites result in minor localized irritation, but severe cases can develop necrotic lesions, ulceration, and systemic symptoms (loxoscelism) requiring medical attention.
Safety Recommendations
Shake out shoes and clothing left on the floor, wear gloves when moving stored items or firewood, and seal cracks in homes. If bitten, clean the area and seek medical evaluation.
Habitat & Behavior
Habitat & Range
Found primarily in the Midwestern and Southern United States. Prefers warm, dry, undisturbed habitats such as attics, basements, closets, woodpiles, and outbuildings.
Behavior & Temperament
Reclusive, nocturnal hunters that typically flee from disturbance. They are not aggressive and generally only bite when trapped against human skin, such as inside clothing or shoes.
Diet & Prey
Feeds primarily on small insects such as cockroaches, crickets, and other soft-bodied arthropods, actively hunting them down near their retreat webs.
Seasonal Activity
Most active during spring, summer, and fall. During colder winter months, they seek shelter indoors or in protected outdoor crevices to overwinter.
Description
The brown recluse is a reclusive, nocturnal hunter famous for its distinct violin-shaped marking and medically significant bite. While often feared, it rarely interacts with humans unless accidentally trapped, playing a valuable role in controlling household insect populations.
Key Features
Uniform violin-shaped mark on the cephalothorax, six eyes arranged in three pairs, uniform color without abdominal patterns, and long, thin legs.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and male southern house spiders (Kukulcania hibernalis) are often mistaken for brown recluses due to color, but can be distinguished by eye arrangement and absence of the violin mark.
Life Cycle
Females produce several silk egg sacs containing around 30 to 50 eggs during the warmer months. Spiderlings go through multiple molts, and the lifespan can reach up to two to three years.
Ecological Importance
Serves as an effective predator of household and garden insect pests, helping to naturally regulate populations of cockroaches, crickets, and other arthropods.
Conservation Status
Not evaluated by the IUCN, but populations are generally stable and robust throughout its native geographic range.
Interesting Facts
Unlike many spiders that spin complex webs to catch prey, the brown recluse is an active nocturnal hunter that roams for food. They can also survive for months without food or water.
Photography Tips
Use macro lenses, gentle natural lighting or a diffused flash, and maintain a safe distance. Capture a clear top-down view to accurately show the eye arrangement and violin marking.
Identified: 2026-10-04T01:52:49.946048