Brown Recluse Spider, Fiddleback Spider, Violin Spider
Loxosceles reclusa
Sicariidae (Recluse Spiders), Order Araneae
Physical Description
Small, matte-textured spider with a cephalothorax that typically features a dark brown violin-shaped marking. The abdomen is uniform in color without spots or stripes, covered in fine hairs giving it a velvety appearance.
Size Estimate
Body length 6-20mm (1/4 to 3/4 inch); leg span approximately the size of a United States quarter.
Coloration & Markings
Light to medium brown, though colors vary from whitish to dark brown. Distinguishing 'violin' mark on the dorsal cephalothorax with the neck of the violin pointing toward the abdomen.
Web Type
Irregular, sticky, off-white/grayish 'tangle' webs built in dark, undisturbed corners; used for retreat rather than prey capture.
Eye Arrangement
Six eyes arranged in three pairs (dyads) in a semi-circle; this is a key diagnostic feature as most spiders have eight eyes.
Leg Characteristics
Long, slender legs with a uniform color; they lack conspicuous spines (macrosetae) or banding patterns.
Venom & Safety Information
Venom Information
Cytotoxic and hemolytic venom containing the enzyme sphingomyelinase D, which can cause dermonecrotic lesions (tissue death).
Medical Significance
Medically significant. While most bites heal without complication, some can lead to necrotic ulcers or, rarely, systemic 'loxoscelism' (fever, chills, rashes).
Safety Recommendations
Shake out shoes and clothing; use glue traps for monitoring; seal cracks in walls. If bitten, seek medical attention if the wound spreads, becomes painful, or shows signs of infection.
Habitat & Behavior
Habitat & Range
Commonly found in the Central and Midwestern United States. They prefer dark, dry, undisturbed areas like attics, basements, woodpiles, and closets.
Behavior & Temperament
Reclusive and non-aggressive; bites usually occur only when the spider is pressed against the skin (e.g., inside clothing or bedding).
Diet & Prey
Scavengers and hunters of soft-bodied insects like silverfish, crickets, and cockroaches. They use venom to submerge prey quickly.
Seasonal Activity
Most active from spring through summer; sightings often peak in June and July during mating season.
Description
The Brown Recluse is a shy, synanthropic species often misunderstood. It is easily identified by its unique eye arrangement and violin mark, yet it is frequently confused with harmless house spiders. It plays a role in controlling indoor pest populations.
Key Features
Six eyes in three pairs; violin-shaped marking; uniform coloration on legs and abdomen; reclusive behavior.
Similar Species
Kukulcania hibernalis (Southern House Spider), Tegenaria species (Hobo Spiders), and various Wolf Spiders (Lycosidae).
Life Cycle
Females produce 1-5 egg sacs over their lifetime (1-2 years). Spiderlings take about a year to reach maturity. They are known for extreme resilience to hunger and dehydration.
Ecological Importance
Primary predator of household pests, performing natural biological control of silverfish and cockroach nymphs.
Conservation Status
Not listed on IUCN Red List; populations are stable and common in human-altered environments.
Interesting Facts
They can survive for months without food or water and are known to be highly resistant to common household pesticides.
Photography Tips
Focus on the dorsal side of the cephalothorax to capture the violin mark and the front of the head to document the six-eye pattern.
User Notes
What spider bite is this
Identified: 2026-06-22T04:38:30.870607