Brown Recluse Spider, Fiddle-back Spider, Violin Spider, Recluse 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 spider has a relatively uniform, violin-shaped marking on its cephalothorax (the fiddle pointing toward the abdomen). The body is elongate and softly textured with fine hairs rather than heavy spines. The abdomen is typically oval, uniform in color without distinct patterns, and varies in shade from tan to dark brown.
Size Estimate
Body length ranges from 6 to 20 millimeters (approximately 1/4 to 3/4 inch), with a leg span that can reach up to 25 to 30 millimeters (1 inch). The specimen in the jar appears to be a medium-sized adult or large sub-adult.
Coloration & Markings
Base coloration ranges from light tan to dark brown. The defining marking is the dark brown violin shape on the dorsal carapace, with the neck of the violin pointing backward toward the abdomen. The legs are generally uniform in color without prominent banding.
Web Type
Builds irregular, sticky, disorganized retreat webs, often described as sheet-like or cobweb-like, typically constructed in dark, undisturbed areas such as under boxes, inside woodpiles, or behind furniture.
Eye Arrangement
Possesses six eyes instead of the typical eight found in most spiders. The eyes are arranged in three pairs (dyads): one median pair and two lateral pairs, forming a semicircular pattern.
Leg Characteristics
Legs are long, slender, and uniformly colored without spines, stripes, or distinct banding. They are held somewhat flat and spread out when at rest.
Venom & Safety Information
Venom Information
Possesses a necrotic, cytotoxin-containing venom dominated by the enzyme sphingomyelinase D. While many bites result in mild localized reactions, some can cause significant tissue necrosis (dermonecrosis) and systemic symptoms.
Medical Significance
Medically significant. Bites can occasionally lead to necrotic skin lesions that are slow to heal, though severe systemic reactions (loxoscelism) are rare. Immediate medical evaluation is recommended if a bite causes an open sore or systemic illness.
Safety Recommendations
Shake out shoes and clothing left on the floor before wearing, wear gloves when moving stored items or firewood, and use a jar and card to safely relocate individuals found indoors outdoors.
Habitat & Behavior
Habitat & Range
Endemic to the central and southern United States, ranging from Nebraska south to Texas and east to Ohio and Georgia. Prefers dark, dry, sheltered microhabitats such as woodpiles, basements, attics, closets, and undisturbed storage areas.
Behavior & Temperament
Reclusive, nocturnal, and non-aggressive. They typically flee when disturbed and only bite when pressed against human skin, such as when trapped inside clothing or shoes.
Diet & Prey
Predatory generalist feeding primarily on small insects such as roaches, crickets, and silverfish, which they capture by active hunting near their retreat webs.
Seasonal Activity
Most active during spring, summer, and autumn months when foraging for prey. During winter, they seek shelter indoors or in deep crevices to overwinter.
Description
The Brown Recluse is a modest yet infamous inhabitant of dark corners and undisturbed spaces across the central and southern United States. Recognized instantly by the dark violin marking on its back and its unusual six-eyed arrangement, this spider plays an important insect-control role while requiring respectful caution from human homeowners.
Key Features
1) A distinct dark violin-shaped marking on the dorsal cephalothorax. 2) Exactly six eyes arranged in three dyads. 3) Uniformly colored, long, slender legs lacking spines or bands. 4) Unmarked, uniform brown to tan abdomen.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and male southern house spiders (Kukulcania hibernalis) are frequently mistaken for the brown recluse. They can be distinguished by examining the eye pattern, leg spination, and the absence of the true violin marking.
Life Cycle
Females produce several white, silk egg sacs containing around 30 to 50 eggs each during the warmer months. Spiderlings undergo multiple molts over a lifespan that can extend up to 2 to 4 years.
Ecological Importance
Serves as an effective natural predator of household pests such as cockroaches, crickets, and other nuisance insects, contributing to local pest suppression.
Conservation Status
Not evaluated by the IUCN, but populations are generally stable and widespread throughout their native geographic range.
Interesting Facts
Brown recluses can survive for months without food or water in extreme environments. Despite their fearsome reputation, they lack the specialized mouthparts needed to easily bite through thicker areas of human skin.
Photography Tips
Photograph from above to clearly capture the dorsal violin marking and body proportions. Ensure adequate indirect lighting to avoid harsh shadows, and maintain a safe distance using a macro lens.
Identified: 2026-08-30T19:05:49.005808