Brown Recluse Spider, Violin Spider, Fiddleback Spider
Loxosceles reclusa
Sicariidae (Six-eyed Sicariid Spiders), Order Araneae. Key family characteristics include having only six eyes arranged in distinct dyads.
Physical Description
The brown recluse has a uniform light brown to tan cephalothorax with a distinct darker violin-shaped marking pointing toward the abdomen. The abdomen is oval, covered in fine, short hairs, and typically uniformly colored without prominent bands or stripes. The specimen appears deceased, with legs curled tightly in a typical post-mortem posture.
Size Estimate
Body length is approximately 6 to 10 millimeters, with a leg span of roughly 20 to 25 millimeters, which is standard for an adult specimen.
Coloration & Markings
Characterized by a light brown to yellowish-brown body. The defining feature is the dark fiddle or violin shape on the dorsal cephalothorax, with the neck of the violin pointing backward. The abdomen is uniformly pale brown, grayish, or dark brown depending on recent feeding.
Web Type
Irregular, sticky retreat webs spun in dark, undisturbed areas rather than symmetric orb webs. Used primarily as a shelter rather than an active trap.
Eye Arrangement
Six eyes arranged in three pairs (dyads): one pair at the front and a pair on each side, which is a key diagnostic feature for the Sicariidae family.
Leg Characteristics
Long, thin, uniformly colored brown legs devoid of prominent spines, stripes, or strong banding patterns. Legs typically curl inward tightly when the spider dies or is defensive.
Venom & Safety Information
Venom Information
Contains a potent necrotic venom primarily composed of the enzyme sphingomyelinase D, which destroys cell membranes and causes localized tissue breakdown.
Medical Significance
Medically significant. Bites can result in severe necrotic lesions, ulceration, and slow-healing wounds. Most bites heal without complication, but systemic reactions (loxoscelism) can occasionally occur, requiring medical evaluation.
Safety Recommendations
Wear gloves when handling stored items in dark areas, shake out shoes and clothing before dressing, and safely relocate or eliminate spiders using a jar and piece of paper if found indoors.
Habitat & Behavior
Habitat & Range
Native to the central and southern United States, found in warm, dry, undisturbed habitats such as woodpiles, basements, attics, closets, and behind furniture indoors.
Behavior & Temperament
Reclusive, nocturnal hunters that actively forage for prey rather than waiting in a web. Not aggressive, but will bite if trapped against skin inside clothing or bedding.
Diet & Prey
Primarily feeds on small insects such as cockroaches, crickets, and silverfish, subduing them with potent venom.
Seasonal Activity
Most active during spring and summer months, though indoor populations remain active year-round in heated buildings.
Description
The brown recluse spider is one of North America's most misunderstood yet medically important arachnids. Recognizable by its characteristic violin marking and six-eye arrangement, it prefers quiet, undisturbed locations away from human traffic.
Key Features
Presence of a dark violin-shaped marking on the cephalothorax and exactly six eyes arranged in three pairs, combined with uniformly colored, unbanded legs.
Similar Species
Cellar spiders (Pholcidae), male southern house spiders (Kukulcania hibernalis), and grass spiders (Agelenidae), all of which lack the specific violin marking and have eight eyes.
Life Cycle
Females produce several white, silk egg sacs containing up to 50 eggs each during the warmer months. Spiderlings molt multiple times and can live for 1 to 2 years.
Ecological Importance
Serves as an effective predator of household insect pests, helping to naturally regulate populations of cockroaches and other crawling insects.
Conservation Status
Not evaluated by the IUCN, highly secure and widespread across its native range, often considered a pest species in human habitations.
Interesting Facts
Brown recluses can survive for months without food or water in extremely dry indoor environments and are exceptionally adapted to human structures.
Photography Tips
Photograph from above in natural lighting to clearly capture the dorsal violin marking on the cephalothorax and the eye arrangement without using harsh direct flash.
Identified: 2026-09-13T12:01:56.576376