Brown Recluse Spider, Fiddleback, Violin Spider
Loxosceles reclusa (likely or related Loxosceles species)
Sicariidae (Six-eyed Sicariid Spiders), Order Araneae. Key family characteristics include the unique arrangement of six eyes in three dyads and necrotic venom.
Physical Description
The spider has a uniform, velvety appearance with a distinct violin-shaped marking on the dorsal cephalothorax. The body is divided into a cephalothorax and an oval abdomen, lacking strong patterns or spines.
Size Estimate
Body length approximately 6 to 20 mm, with a leg span ranging from 20 to 30 mm.
Coloration & Markings
Uniform yellowish-brown to dark brown coloration. The defining characteristic is the darker violin or fiddle shape on the cephalothorax, with the neck pointing backward.
Web Type
Irregular, asymmetric retreat web composed of sticky, disorganized silken threads constructed in dark, undisturbed areas.
Eye Arrangement
Six eyes arranged in three pairs (dyads): one pair centrally and two lateral pairs, which is a key diagnostic feature of the Sicariidae family.
Leg Characteristics
Long, thin, delicate legs of a uniform color lacking prominent spines, bands, or bright patterns. They are typically held flat or spread widely when resting.
Venom & Safety Information
Venom Information
Contains the potent enzyme sphingomyelinase D, which is dermonecrotic and destroys cell membranes, potentially causing localized tissue death.
Medical Significance
Medically significant. While many bites result in mild skin irritation, some can cause necrotic lesions, ulceration, and systemic symptoms requiring medical evaluation.
Safety Recommendations
Inspect and shake out stored clothing and shoes before wearing, seal cracks in homes, wear gloves when handling stored items, and seek medical attention if a bite causes a persistent necrotic lesion.
Habitat & Behavior
Habitat & Range
Found primarily in the Midwestern and Southern United States. Prefers warm, dry, undisturbed habitats such as woodpiles, basements, attics, closets, and behind furniture.
Behavior & Temperament
Reclusive, nocturnal, and non-aggressive. They typically flee when disturbed and only bite when trapped against human skin.
Diet & Prey
Active nocturnal hunters feeding primarily on small insects such as cockroaches, crickets, and silverfish.
Seasonal Activity
Most active during late spring, summer, and early autumn, often moving indoors as temperatures drop in winter.
Description
The brown recluse is a reclusive nocturnal hunter well-known for its distinctive violin marking and potent necrotic venom. It plays an important role in controlling indoor pest populations, though caution is warranted in living spaces.
Key Features
Uniform brown coloration, distinct violin-shaped marking on the cephalothorax, lack of spines on the legs, and six eyes arranged in three dyads.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and male southern house spiders (Kukulcania hibernalis), which can be distinguished by eye arrangement and lack of the violin pattern.
Life Cycle
Females produce several white silk egg sacs containing around 50 eggs each during the warm months. Spiderlings develop slowly over a year, molting multiple times before reaching adulthood.
Ecological Importance
Acts as an effective nocturnal predator that helps regulate populations of household insect pests.
Conservation Status
Not evaluated by the IUCN; widespread and locally abundant within its native range.
Interesting Facts
Brown recluses can survive for months without food or water and often hide in shoes, clothing, or bedding, which leads to accidental defensive bites.
Photography Tips
Use macro lenses with gentle, diffused lighting. Maintain a safe distance, focus sharply on the cephalothorax to capture the violin pattern and eye arrangement.
Identified: 2026-09-07T09:25:09.888843