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 tan cephalothorax and abdomen with a smooth texture. The most notable anatomical feature is the dark brown, violin-shaped marking on the dorsal cephalothorax with the neck pointing backward.
Size Estimate
Body length ranges from 6 to 20 millimeters (about 0.25 to 0.75 inches), with a leg span up to 25 to 30 millimeters (1 inch). The specimen appears to be an adult.
Coloration & Markings
Uniform fawn, tan, or dark brown coloration without stripes or multi-colored patterns on the abdomen. The distinctive violin marking on the cephalothorax is dark brown or black.
Web Type
Irregular, sticky, off-white to grayish silk retreat webs constructed in dark, undisturbed areas rather than classic orb webs.
Eye Arrangement
Six eyes arranged in three pairs (dyads) forming a semicircle across the front of the cephalothorax: one pair in front and one pair on each side, which is diagnostic for the family Sicariidae.
Leg Characteristics
Long, thin, uniformly colored legs lacking prominent spines, bands, or bright patterns. They are held flat and spread outward when resting or running.
Venom & Safety Information
Venom Information
Contains a potent necrotic venom featuring the active enzyme sphingomyelinase D, which destroys cell membranes and causes localized tissue destruction.
Medical Significance
Medically significant. Bites can cause severe dermonecrotic lesions, ulceration, and systemic symptoms (loxoscelism), requiring medical evaluation and prompt treatment.
Safety Recommendations
Wear gloves when moving stored items in dark areas, shake out shoes before wearing, keep bedding away from floors, and gently relocate spiders outdoors using a jar if found.
Habitat & Behavior
Habitat & Range
Found primarily in the central and southern United States, inhabiting dark, dry, undisturbed places such as woodpiles, basements, attics, closets, and behind furniture.
Behavior & Temperament
Reclusive, nocturnal, and non-aggressive. They hide during the day and actively forage at night, biting humans only when trapped against the skin.
Diet & Prey
Primarily preys on small insects such as cockroaches, crickets, and other soft-bodied arthropods, hunting them down rather than catching them in a traditional web.
Seasonal Activity
Most active during spring, summer, and early autumn. In cooler months, they seek shelter indoors to overwinter in heated structures.
Description
The brown recluse spider is a secretive, nocturnal hunter best known for its signature violin-shaped marking. While often feared due to its necrotic venom, it is naturally shy and prefers dark, hidden microhabitats away from human traffic.
Key Features
Uniformly light brown color, lack of spines or patterns on the legs, absence of abdominal patterns, and the distinct dark violin shape on the cephalothorax paired with six eyes.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and wolf spiders (Lycosidae), which often have patterns on their bodies, eight eyes, and spiny legs.
Life Cycle
Females produce several silken egg sacs containing around 50 eggs each during the warmer months. Spiderlings mature slowly over roughly a year, going through multiple molts.
Ecological Importance
Serves as an effective natural predator that helps control populations of household pests such as roaches, silverfish, and crickets.
Conservation Status
Not threatened or evaluated by the IUCN; highly adaptable and abundant across its native range.
Interesting Facts
Brown recluses can survive for months without food or water, and their venom contains specialized enzymes evolved specifically to rapidly digest prey tissues.
Photography Tips
Use a macro lens with a tripod and diffuse lighting. Focus sharply on the eye arrangement and the dorsal cephalothorax to capture the diagnostic violin marking safely from a distance.
Identified: 2026-09-10T16:05:11.482121