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 features a uniform light brown to dark brown body with delicate, velvety hairs. The cephalothorax typically bears a distinct dark violin-shaped marking with the neck pointing toward the abdomen. The abdomen is oval, uniformly colored without patterns, and slightly elongated.
Size Estimate
Body length ranges from 6 to 20 mm (about 1/4 to 3/4 inch), with a leg span of roughly 20 to 30 mm. The specimens shown on the glue trap appear to be adults and sub-adults.
Coloration & Markings
Coloration ranges from yellowish-tan to dark brown. The most notable marking is the dark fiddle-shaped (violin) pattern on the dorsal surface of the cephalothorax. The legs are generally uniform in color without distinct bands or stripes.
Web Type
They construct irregular, sticky retreat webs rather than organized orb webs. These webs are typically built in dark, undisturbed places like crevices, under furniture, in closets, or behind baseboards.
Eye Arrangement
Uniquely, they possess six eyes arranged in three pairs (dyads) separated by spaces: one pair in front and two pairs along the sides. This is a defining trait for the family Sicariidae.
Leg Characteristics
Legs are long, thin, and spindly, spreading wide in a flattened posture when resting. They lack prominent spines or distinct color banding, and have fine hairs rather than heavy spines.
Venom & Safety Information
Venom Information
Possesses a potent necrotic venom containing sphingomyelinase D, which destroys cell membranes and can cause localized tissue destruction (dermonecrosis).
Medical Significance
Medically significant. While many bites result in mild localized irritation or heal without scarring, some can cause severe necrotic lesions (necrotic arachnidism) requiring medical intervention.
Safety Recommendations
Wear gloves when handling stored items in basements or attics, shake out shoes before wearing, keep beds away from walls, and use professional pest management if infestations occur.
Habitat & Behavior
Habitat & Range
Native to the central and southern United States, ranging from the Midwest down to Texas and the Gulf Coast. They prefer dry, dark, undisturbed microhabitats such as woodpiles, basements, attics, and closets.
Behavior & Temperament
Reclusive, nocturnal hunters. They are non-aggressive and typically bite only when trapped against human skin, such as when putting on clothing or rolling onto one in bed.
Diet & Prey
Active nocturnal hunters feeding primarily on small insects such as cockroaches, crickets, and silverfish by tracking them down or ambushing them near their retreat.
Seasonal Activity
Most active during warmer months from spring through autumn, though they remain active year-round in indoor heated environments.
Description
The brown recluse spider is one of North America's most misunderstood yet medically important species. Easily identified by the characteristic violin marking on its cephalothorax and its unusual six-eyed arrangement, this spider prefers solitude in dark, undisturbed corners of human structures.
Key Features
Uniformly colored abdomen, distinctive violin-shaped mark on the cephalothorax, and six eyes arranged in three pairs.
Similar Species
Cellar spiders (Pholcidae), male southern house spiders (Kukulcania hibernalis), and grass spiders (Agelenidae). These can be distinguished by examining the eye pattern and lack of the violin marking.
Life Cycle
Females produce several egg sacs containing roughly 30 to 50 eggs each during spring and summer. Spiderlings go through multiple molts over a lifespan that can exceed 1 to 2 years.
Ecological Importance
Acts as an effective nocturnal predator that helps regulate populations of household insect pests.
Conservation Status
Not evaluated by the IUCN, but highly abundant and secure throughout its native range.
Interesting Facts
Brown recluses can survive for months without food or water in harsh conditions, and their venom contains enzymes adapted specifically to pre-digest tissue.
Photography Tips
Use macro lenses with adequate lighting while keeping a safe distance. Focus sharply on the dorsal cephalothorax to capture the violin pattern and the eye arrangement clearly.
Identified: 2026-09-26T14:40:49.316967