Brown Recluse Spider, Violin Spider, Fiddleback
Loxosceles reclusa
Sicariidae (Six-eyed Sicariid Spiders), Order Araneae. Key family characteristics include the presence of only six eyes arranged in three dyads and a specialized venom profile containing sphingomyelinase D.
Physical Description
The brown recluse has a uniform color palette with a distinct violin-shaped marking on its cephalothorax, pointing toward the abdomen. It lacks spines on its legs, possessing fine hairs instead, and has a rather plain, oval-shaped velvety abdomen.
Size Estimate
Body length typically ranges from 6 to 20 millimeters (0.24 to 0.79 inches), with a leg span reaching up to 20 to 30 millimeters. The specimen in the image appears small, roughly 10 millimeters in total span, potentially an adult male or a late-stage juvenile.
Coloration & Markings
Colors range from light tan to dark brown. The defining marking is the dark brown violin pattern on the dorsal carapace, with the neck of the violin pointing backward. The abdomen is uniformly colored without stripes or complex patterns.
Web Type
Does not build traditional orb webs. Instead, it constructs irregular, sticky, disorganized retreat webs in dark, quiet, undisturbed crevices, usually serving as daytime shelter.
Eye Arrangement
Uniquely possesses six eyes arranged in three distinct pairs (dyads): one median pair and two lateral pairs, which is a key diagnostic feature separating Sicariidae from many other families.
Leg Characteristics
Long, slender, and uniformly colored legs without noticeable banding or prominent spination. They are typically held in a slightly sprawled posture when resting.
Venom & Safety Information
Venom Information
Contains a potent necrotic venom dominated by the enzyme sphingomyelinase D, which destroys cell membranes and can cause localized tissue destruction (dermonecrosis).
Medical Significance
Medically significant. Most bites result in minor localized irritation, but a subset can develop into necrotic ulcers that require professional medical attention to prevent severe tissue damage.
Safety Recommendations
Shake out shoes and clothing before getting dressed, wear gloves when handling stored items, and carefully relocate spiders using a jar and piece of paper if found indoors.
Habitat & Behavior
Habitat & Range
Found natively in the central and southern United States. They prefer dry, sheltered microhabitats such as woodpiles, under rocks, or indoors within dark undisturbed areas like closets, basements, and attics.
Behavior & Temperament
Timid and nocturnal hunters. They actively avoid light and human contact, fleeing when disturbed rather than aggressively defending themselves, biting only when pressed directly against skin.
Diet & Prey
Primarily preys on small insects such as cockroaches, crickets, and silverfish, hunting them by actively foraging near their retreat rather than waiting in an extensive web.
Seasonal Activity
Most active during spring, summer, and fall. During winter, they typically seek shelter indoors or in protected outdoor crevices to enter a state of dormancy.
Description
The brown recluse is a reclusive, nocturnal hunter recognized by its violin-shaped marking and unusual six-eyed arrangement. While medically significant due to its necrotic venom, it is non-aggressive and generally bites only when accidentally trapped against the body.
Key Features
Distinctive violin-shaped marking on the cephalothorax, uniform brown legs without bands, lack of abdominal patterns, and six eyes arranged in three pairs.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and wolf spiders (Lycosidae) are frequently confused with the brown recluse, but lack the violin marking and six-eye configuration.
Life Cycle
Females produce several egg sacs containing around 30 to 50 eggs each during the warm months. Spiderlings go through multiple molts, taking about a year to reach maturity, and can live for several years.
Ecological Importance
Acts as an effective predator of household and outdoor insect pests, helping to regulate populations of roaches, crickets, and other small arthropods.
Conservation Status
Not evaluated by the IUCN, but highly abundant and secure within its native geographic range.
Interesting Facts
Brown recluses can survive for months without food or water in extremely dry environments. They are among the few North American spiders whose venom can cause dermonecrotic lesions.
Photography Tips
Use a macro lens with good natural lighting or a diffused flash. Maintain a safe distance, focus on the dorsal carapace to capture the violin pattern and eye arrangement clearly.
Identified: 2026-09-13T21:45:18.672198