Brown Recluse Spider, Fiddleback Spider, Violin Spider
Loxosceles reclusa
Sicariidae (Six-eyed Sicariid Spiders), Order Araneae. Key family characteristics include the presence of only six eyes arranged in distinct dyads.
Physical Description
The brown recluse features a uniform, delicate body shape with long, thin legs. The cephalothorax is typically light brown to tan, featuring a darker violin-shaped marking with the neck pointing toward the abdomen. The abdomen is oval, covered in fine, short hairs, and lacks distinct patterns.
Size Estimate
Body length typically ranges from 6 to 20 millimeters (0.24 to 0.79 inches), with a leg span of around 20 to 30 millimeters. This specimen appears to be an adult or sub-adult of average size for the species.
Coloration & Markings
Coloration ranges from yellowish-tan to dark brown. The defining marking is the dark violin-shaped pattern on the dorsal carapace. The abdomen is uniformly colored without stripes or bands, varying from cream to dark brown depending on recent meals.
Web Type
Builds irregular, asymmetric, sticky retreat webs rather than traditional orb webs. These webs are typically constructed in dark, undisturbed areas such as under objects, in crevices, or inside wall voids.
Eye Arrangement
Uniquely possesses six eyes arranged in three pairs (dyads) separated by spaces: one pair anteriorly and a pair on each lateral side. This contrasts with the typical eight-eyed arrangement of most spiders.
Leg Characteristics
Legs are long, slender, and uniformly colored without spines, stripes, or distinct banding patterns. They are held out flat when resting or moving along surfaces.
Venom & Safety Information
Venom Information
Possesses a potent necrotic venom containing the enzyme sphingomyelinase D. The venom causes localized tissue destruction, cell death, and dermonecrosis at the bite site.
Medical Significance
Medically significant. While many bites result in minor localized irritation, severe envenomation can cause deep necrotic skin lesions, ulcers, and systemic reactions (loxoscelism) requiring medical attention.
Safety Recommendations
Inspect and shake out clothing and shoes before wearing. Wear gloves when moving firewood or stored items in dark areas. Relocate indoor spiders using a container and a piece of paper.
Habitat & Behavior
Habitat & Range
Found primarily in the Midwestern and Southern United States. Prefers dark, warm, dry environments such as woodpiles, basements, attics, closets, and undisturbed storage areas.
Behavior & Temperament
A nocturnal, sedentary hunter that avoids light and human contact. They are reclusive by nature and will only bite when trapped against the skin, such as being compressed inside clothing or bedding.
Diet & Prey
Feeds primarily on small insects such as roaches, crickets, and silverfish, actively hunting them near its retreat or catching them in its irregular web.
Seasonal Activity
Most active during spring and summer months when hunting and mating occur. During winter, they seek shelter indoors and remain mostly dormant.
Description
The brown recluse is a notoriously misunderstood synanthropic spider known for its characteristic violin marking. While shy and non-aggressive, its potent necrotic venom warrants caution in homes where populations establish.
Key Features
Six eyes arranged in three pairs, a distinct violin-shaped marking on the cephalothorax, uniformly colored legs without bands, and a plain, unpatterned abdomen.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and male southern house spiders (Kukulcania hibernalis) are frequently mistaken for brown recluses due to their brown coloration and long legs.
Life Cycle
Females produce several spherical, off-white egg sacs containing 30 to 50 eggs during the warmer months. Spiderlings emerge after about a month and undergo multiple molts, living for an average of 1 to 2 years.
Ecological Importance
Acts as an effective natural predator of household pests, helping to control populations of insects like cockroaches and earwigs within its native range.
Conservation Status
Not evaluated by the IUCN, but populations are secure and abundant across their native geographic range in North America.
Interesting Facts
Brown recluses can survive for months without food or water in extreme environments. Despite their fearsome reputation, they rarely bite unless directly trapped against human skin.
Photography Tips
Maintain a safe distance and use macro lenses for close-up shots. Focus sharply on the cephalothorax to capture the diagnostic violin pattern and eye arrangement.
Identified: 2026-08-14T22:39:56.649601