Brown Recluse, Fiddleback Spider, Violin Spider
Loxosceles reclusa
Sicariidae (Six-eyed Sicariid Spiders), Order Araneae
Physical Description
Small, reclusive spider with a flattened, uniform light-to-medium brown appearance. The cephalothorax features a dark brown, violin-shaped (fiddle) mark pointing backward toward the abdomen. The abdomen is unpotted, uniform in color, and covered in fine, short hairs, giving it a soft, velvety texture.
Size Estimate
Body length typically 6-20 mm (0.25 to 0.75 inches), with a leg span often around 25 mm (1 inch). The visible specimen shows characteristic long, slender leg proportions typical of an adult or sub-adult Loxosceles.
Coloration & Markings
Uniform yellowish-tan to dark brown overall. Legs are plain without distinct bands, stripes, or contrasting spots. The key identifier is the dark brown, violin-shaped marking located on the dorsal side of the cephalothorax.
Web Type
Irregular, sticky, sheet-like web or tangle web built in undisturbed, dark, sheltered locations such as attics, closets, behind furniture, or inside cardboard boxes. Not an orb-weaver; the web serves primarily as a retreat rather than a aerial trap.
Eye Arrangement
Six eyes arranged in three pairs (dyads) forming a distinct semicircle: one anterior pair and two lateral pairs. Unlike most spiders that have eight eyes, this six-eye configuration is a crucial diagnostic trait.
Leg Characteristics
Long, thin, delicate legs extending outward from the body. Completely uniform in color with no dark bands, rings, or prominent spines—only covered in short fine setae.
Venom & Safety Information
Venom Information
Cytotoxic (necrotic) venom containing the enzyme sphingomyelinase D. Venom causes tissue breakdown and localized cellular destruction, potentially leading to necrotic cutaneous lesions.
Medical Significance
Medically significant. Most bites result in minor localized redness and swelling, but a small percentage can cause loxoscelism—a necrotic skin lesion that turns into a dark ulcer. Systemic reactions (hemolysis, renal failure) are extremely rare. Seek medical evaluation if bitten or suspected.
Safety Recommendations
Shake out clothes, towels, and shoes stored in dark spaces before use. Move beds away from walls and remove bed skirts touching the floor. If bitten, clean the area with soap and water, apply ice, elevate the site, and seek medical attention.
Habitat & Behavior
Habitat & Range
Native to the central and southern United States (from Texas to Florida, north to Iowa and Ohio). Prefers warm, dark, dry, undisturbed indoor environments like cellars, crawlspaces, wall voids, cardboard boxes, and rarely used clothing or shoes.
Behavior & Temperament
Reclusive, nocturnal, and non-aggressive. Prefers to flee or hide rather than bite. Bites usually occur only when pressed firmly against human skin (e.g., inside rolled-over bedding, shoes, or clothing being put on).
Diet & Prey
Nocturnal opportunistic hunter that feeds on small insects such as silverfish, cockroaches, crickets, ants, and other small arthropods. Capable of surviving long periods without food or water.
Seasonal Activity
Active year-round in temperature-controlled indoor environments. In natural or unheated spaces, activity peaks during late spring through autumn, with mating occurring primarily in spring.
Description
The brown recluse is a shy, synanthropic spider known for its distinct violin-shaped pattern on its head region. Highly adapted to dry human habitations, it remains hidden during daylight and hunts small pests during the night. Despite its notorious reputation, it rarely bites unless directly crushed against skin.
Key Features
1. Distinct violin-shaped dark mark on cephalothorax. 2. Exactly six eyes in three pairs. 3. Uniform brown abdomen without stripes or spots. 4. Plain legs with no dark banding or heavy spines.
Similar Species
frequently confused with Kukulcania hibernalis (Southern House Spider - longer palps, different eye arrangement), Scytodes species (Spitting Spiders - spotted legs), and Tegenaria/Eratigena species (Funnel Web/Hobo Spiders - patterned abdomen and 8 eyes).
Life Cycle
Females lay off-white egg sacs in hidden retreats containing 40–50 eggs each. Spiderlings molt several times before reaching maturity. Long-lived for a small spider, often living 1 to 3 years or more.
Ecological Importance
Serves as an effective indoor pest controller by consuming common household insects including silverfish, cockroach nymphs, and carpet beetles.
Conservation Status
Not listed on the IUCN Red List. Common and stable throughout its native range.
Interesting Facts
Brown recluses can go for over six months without food or water. The necrotic component of their venom, sphingomyelinase D, is rare in animal venoms and found mainly in Sicariid spiders and a few bacteria.
Photography Tips
Photograph directly from above (dorsal view) to capture the violin pattern clearly on the cephalothorax, and get a clear close-up of the front of the head to verify the six-eye layout.
Identified: 2026-07-25T15:42:19.765915