Brown Recluse Spider, Violin Spider, Fiddleback
Loxosceles reclusa
Sicariidae (Six-eyed Sicariid Spiders), Order Araneae. Key family characteristics include having six eyes arranged in three dyads and a specialized venom profile.
Physical Description
The brown recluse has a distinctively uniform, matte appearance with a violin-shaped marking (fiddleback) on the dorsal cephalothorax. The body is divided into a clean cephalothorax and an elongated, oval abdomen that lacks conspicuous patterns or bright colors.
Size Estimate
Body length typically ranges from 6 to 20 millimeters (0.25 to 0.75 inches), with a leg span reaching up to 25 to 30 millimeters (1 inch). The specimen shown appears to be a medium-sized adult or a well-developed juvenile.
Coloration & Markings
Colors range from yellowish-tan to dark brown. The defining marking is the dark violin shape on the cephalothorax with the neck pointing backward. The abdomen is a uniform solid shade of tan, brown, or grayish without bands, stripes, or spots.
Web Type
They construct irregular, off-center, sticky retreat webs rather than organized orb webs. These retreat webs are typically built in dark, undisturbed, sheltered crevices such as under rocks, inside woodpiles, or within wall voids.
Eye Arrangement
Unlike most spiders that have eight eyes, brown recluses possess only six eyes arranged in three distinct pairs (dyads): one pair centrally and a pair on each side.
Leg Characteristics
Legs are long, thin, slender, and uniformly colored without noticeable dark banding, spines, or contrasting rings. They are held in a sprawling posture when resting.
Venom & Safety Information
Venom Information
Possesses a potent necrotic venom containing the active enzyme sphingomyelinase D, which destroys cell membranes and can cause localized tissue destruction (dermonecrotic lesions).
Medical Significance
Medically significant. While many bites result in minor localized irritation, severe bites can cause necrotic ulcers that take weeks or months to heal. Systemic reactions are rare but possible. Seek medical attention if a necrotic lesion develops.
Safety Recommendations
Shake out shoes and clothing left on the floor before wearing, wear gloves when moving stored items in dark spaces, and carefully relocate spiders using a container and piece of paper if found indoors.
Habitat & Behavior
Habitat & Range
Native to the central and southern United States, ranging from the Midwest down to the Gulf Coast and westward into Texas. Prefers dry, dark, undisturbed microhabitats both outdoors (under bark and rocks) and indoors (closets, attics, basements, and behind furniture).
Behavior & Temperament
Reclusive, nocturnal hunters that actively forage at night. They are non-aggressive and will only bite when trapped against human skin, such as when putting on clothing or rolling over in bed.
Diet & Prey
Primarily preys on small insects such as cockroaches, crickets, and silverfish, subduing them with potent venom after a quick ambush.
Seasonal Activity
Most active during spring, summer, and early autumn. In colder months, they seek shelter indoors and become largely sedentary.
Description
The brown recluse is one of North America's most misunderstood spiders. Known for its characteristic fiddle-shaped marking and nocturnal habits, it plays a valuable role in controlling household insect populations while maintaining its namesake secretive lifestyle.
Key Features
Six eyes in three pairs, a distinct violin-shaped dorsal mark on the cephalothorax, and uniformly colored, unbanded legs combined with an unpatterned abdomen.
Similar Species
Cellar spiders (Pholcidae) have much longer legs and eight eyes; grass spiders (Agelenidae) have prominent spinnerets and banded legs; male crevice weavers (Kukulcania hibernalis) are often mistaken for recluses due to color, but have a very different velvety texture and eye cluster.
Life Cycle
Females produce several white, silk egg sacs containing around 30 to 50 eggs each during the warmer months. Spiderlings molt multiple times as they grow, reaching adulthood in roughly a year. Total lifespan can exceed two years.
Ecological Importance
Acts as an effective apex predator for indoor and outdoor pest insects, helping to naturally regulate populations of cockroaches and other household pests.
Conservation Status
Not evaluated by the IUCN, but populations are secure and abundant across their native geographic range.
Interesting Facts
Brown recluses can survive for months without food or water in harsh conditions, making them exceptionally resilient indoor inhabitants.
Photography Tips
Use macro lenses with natural diffused lighting, maintain a safe working distance, and capture a clear top-down view to accurately show the cephalothorax pattern and eye arrangement.
Identified: 2026-09-30T18:21:34.871622