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 tendency to inhabit dark, undisturbed areas.
Physical Description
The brown recluse has a uniform light brown to yellowish-tan cephalothorax and a slightly darker abdomen. The body is finely covered in short hairs rather than being spiny. A distinctive dark violin-shaped marking is present on the dorsal cephalothorax, with the neck of the fiddle pointing toward the rear.
Size Estimate
Body length ranges from 6 to 20 millimeters (about 1/4 to 3/4 inch), with a leg span of roughly 25 to 50 millimeters (1 to 2 inches). The specimen shown appears to be an adult.
Coloration & Markings
Monochromatic tan to dark brown overall with no prominent bands, stripes, or multicolored patterns on the legs. The hallmark feature is the dark fiddle-shaped marking on the cephalothorax, and the abdomen may display a subtle darker cardiac stripe.
Web Type
Irregular, sticky tangle webs constructed in dark, sheltered retreats rather than symmetrical orb webs. These webs are used primarily as a daytime shelter and egg-laying site rather than an active aerial trap.
Eye Arrangement
Uniquely possesses six eyes arranged in three pairs (dyads) forming a semicircle across the front of the cephalothorax: one pair centrally located and two lateral pairs, which helps distinguish it from most common spiders that have eight eyes.
Leg Characteristics
Long, thin, delicate legs of a uniform light brown color without distinct dark banding, spines, or rings. They are held in a sprawling, outward fashion when at rest.
Venom & Safety Information
Venom Information
Possesses a potent necrotic venom containing the enzyme sphingomyelinase D, which destroys cell membranes and can cause localized tissue destruction (dermonecrosis) around the bite site.
Medical Significance
Medically significant. While many bites result in mild, self-limiting reactions, others can progress to deep, slow-healing open ulcers (necrotic lesions). Systemic reactions are rare but require medical supervision.
Safety Recommendations
Shake out shoes and clothing left on the floor, wear gloves when moving stored items in dark areas, and seal cracks in home foundations. If bitten, clean the area with soap and water, apply ice, and seek medical attention.
Habitat & Behavior
Habitat & Range
Found primarily in the central and southern United States, ranging from mid-Western states down to the Gulf Coast. Prefers dry, sheltered microhabitats such as woodpiles, basements, attics, closets, and behind furniture.
Behavior & Temperament
A nocturnal, timid hunter that actively forages away from its retreat at night. It is non-aggressive and typically bites only when trapped against human skin, such as inside clothing or shoes.
Diet & Prey
Feeds primarily on small crawling insects like cockroaches, crickets, and silverfish, subduing them with venom delivered via its chelicerae during active nocturnal hunts.
Seasonal Activity
Active year-round indoors, with peak foraging and visibility occurring during the warmer spring and summer months when metabolic needs increase.
Description
The brown recluse is one of North America's most misunderstood yet fascinating synanthropic spiders. Easily identified by its distinct violin marking and unique six-eyed arrangement, this nocturnal hunter prefers quiet, undisturbed corners of human dwellings. Though equipped with necrotic venom, it earned its species name 'reclusa' for its shy, retiring nature, strongly preferring flight to fight.
Key Features
Uniformly colored legs without bands, a dark violin-shaped pattern on the cephalothorax pointing backward, and six eyes arranged in three pairs.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and male southern house spiders (Kukulcania hibernalis) are often mistaken for the brown recluse. They can be distinguished by checking for the absence of the violin pattern, having eight eyes instead of six, or displaying distinct leg banding.
Life Cycle
Females produce several spherical, off-white silk egg sacs containing around 30 to 50 eggs each during the warmer months. Spiderlings molt multiple times as they grow, and the species can live for 2 to 4 years.
Ecological Importance
Acts as an effective predator of household insect pests, helping to regulate populations of cockroaches, crickets, and other unwanted arthropods indoors.
Conservation Status
Not evaluated by the IUCN, but populations are generally robust, abundant, and widespread throughout their native geographic range.
Interesting Facts
Brown recluses can survive for months without food or water in harsh conditions, and their venom contains enzymes specifically tailored to rapidly liquefy insect tissue.
Photography Tips
Photograph from above using natural indirect lighting or a macro setup to clearly capture the dorsal cephalothorax pattern and eye arrangement without disturbing the spider.
Identified: 2026-09-19T18:22:20.670176