Brown Recluse Spider, Violin Spider, Fiddleback Spider
Loxosceles reclusa
Sicariidae, Order Araneae. Key family characteristics include six eyes arranged in three dyads and a specialized venom apparatus.
Physical Description
The brown recluse has a distinctively uniform appearance featuring a pear-shaped cephalothorax and an oval abdomen. The surface is covered in fine, short hairs rather than spines. A prominent violin-shaped marking points toward the abdomen on the dorsal cephalothorax.
Size Estimate
Body length ranges from 6 to 20 millimeters, with a leg span reaching up to 25 to 30 millimeters. The pictured specimen appears to be an adult.
Coloration & Markings
Coloration ranges from yellowish-tan to dark brown. The defining marking is the dark violin shape on the cephalothorax. The abdomen is uniformly colored without stripes or complex patterns.
Web Type
Irregular, loose, sticky silken retreat webs usually built in dark, undisturbed corners, crevices, or beneath objects rather than standard orb webs.
Eye Arrangement
Six eyes arranged in three pairs (dyads) forming a semicircle: one pair in front and a pair on each side. This is a primary diagnostic feature of the Sicariidae family.
Leg Characteristics
Long, thin, and spindly legs lacking prominent spines or distinct banding patterns. They are typically held flat or spread out when resting.
Venom & Safety Information
Venom Information
Contains a potent necrotic venom containing the enzyme sphingomyelinase D. This causes localized tissue destruction, cellular damage, and dermonecrosis.
Medical Significance
Medically significant. Bites can result in severe necrotic lesions, ulceration, and systemic symptoms (loxoscelism), requiring professional medical attention.
Safety Recommendations
Wear gloves when moving stored items, shake out shoes and clothing before dressing, reduce clutter in dark areas, and gently relocate spiders outdoors using a cup and card if found inside.
Habitat & Behavior
Habitat & Range
Native to the central and southern United States. Prefers warm, dry, undisturbed microhabitats such as woodpiles, basements, attics, closets, and behind furniture.
Behavior & Temperament
Nocturnal and reclusive. They actively hunt prey away from their retreat at night. They are non-aggressive and typically bite only when trapped against human skin.
Diet & Prey
Primarily preys on small insects like cockroaches, crickets, and other spiders using an active hunting and ambush strategy.
Seasonal Activity
Most active during spring and summer months. During winter, they seek shelter indoors or in protected outdoor crevices to overwinter.
Description
The brown recluse is a shy, nocturnal hunter renowned for its characteristic violin marking. While medically significant, it prefers to avoid human contact entirely, residing quietly in dark crevices where it helps control household insect populations.
Key Features
Uniformly colored legs and abdomen, the distinct violin-shaped dorsal marking on the cephalothorax, and exactly six eyes arranged in three dyads.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and male southern house spiders (Kukulcania hibernalis), which lack the specific six-eye arrangement and violin pattern.
Life Cycle
Females produce several silk egg sacs containing around 50 eggs each during the warmer months. Spiderlings undergo multiple molts over a lifespan of 1 to 2 years.
Ecological Importance
Serves as an effective apex predator of household and outdoor insect pests, helping to naturally regulate populations of cockroaches and other bugs.
Conservation Status
Not evaluated by the IUCN, but populations are secure and widespread within their native geographic range.
Interesting Facts
Brown recluses can survive for months without food or water. Despite their fearsome reputation, they lack the mouthparts to easily pierce thick human skin in many casual encounters.
Photography Tips
Use macro lenses with a safe distance and diffused lighting to highlight the cephalothorax violin marking and the six-eye arrangement without provoking the spider.
Identified: 2026-09-23T18:43:40.625431