Brown Recluse Spider, Violin Spider, Fiddleback
Loxosceles reclusa
Sicariidae (Six-eyed Sicariid Spiders), Order Araneae. Key family characteristics include having only six eyes arranged in three dyads and a distinct cephalothorax shape.
Physical Description
The brown recluse has a uniform light brown to tan cephalothorax and abdomen. The body is relatively smooth with fine, short hairs rather than heavy spines. A defining feature is the dark violin-shaped marking on the dorsal side of the cephalothorax, with the neck of the violin pointing backward.
Size Estimate
Body length is typically around 6 to 20 millimeters (0.24 to 0.79 inches), with a leg span ranging from 20 to 30 millimeters (0.8 to 1.2 inches). The specimen in the photo appears to be a typical adult.
Coloration & Markings
Colors range from yellowish-tan to dark brown. The defining marking is the dark fiddle-shaped pattern on the cephalothorax. The abdomen is uniformly colored without distinct stripes, bands, or patterns, and the legs are typically a solid, unbanded light brown.
Web Type
They build irregular, sticky, disorganized retreat webs rather than symmetrical orb webs. These webs are typically constructed in dark, undisturbed areas such as under woodpiles, in basements, closets, and behind furniture.
Eye Arrangement
Uniquely, they possess six eyes arranged in three pairs (dyads): one pair centrally and a pair on each side. This contrasts with the typical eight eyes found in most other spider families.
Leg Characteristics
The legs are long, slender, and uniformly colored without spines, bands, or distinct patterns. When resting or startled, they often stretch out their legs flat or adopt a defensive posture.
Venom & Safety Information
Venom Information
Possesses a potent necrotic venom containing the enzyme sphingomyelinase D, which destroys cell membranes and causes tissue damage around the bite site.
Medical Significance
Medically significant. While many bites result in mild irritation, severe envenomation can cause dermonecrotic lesions (necrotic arachnidism) that take weeks or months to heal. Systemic reactions are rare but possible. Seek medical attention if a necrotic lesion develops or if systemic symptoms occur.
Safety Recommendations
Shake out shoes and clothing before getting dressed, wear gloves when moving stored items in dark areas, and safely relocate indoor spiders using a jar and piece of paper if found.
Habitat & Behavior
Habitat & Range
Native to the central and southern United States, ranging from the Midwest down to Texas and eastward to Georgia. They prefer warm, dry, dark microhabitats, frequently inhabiting undisturbed indoor spaces like attics, basements, and closets, as well as outdoor environments under rocks and bark.
Behavior & Temperament
Nocturnal hunters that actively forage for prey away from their retreat webs. They are highly reclusive, 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 feed on small insects such as cockroaches, crickets, and other soft-bodied arthropods. They hunt by actively stalking or waiting for prey to wander near their retreat.
Seasonal Activity
Most active during the spring, summer, and fall months when foraging for food and seeking mates. During winter, they typically remain indoors and sheltered.
Description
The brown recluse is a famously misunderstood nocturnal hunter known for its characteristic violin marking. While medically significant due to its necrotic venom, it earned its name from a genuinely shy and retiring nature, preferring to hide in dark, undisturbed places.
Key Features
The combination of a violin-shaped marking on the cephalothorax, uniform unbanded legs, an unmarked abdomen, and six eyes arranged in three dyads.
Similar Species
Cellar spiders (Pholcidae), grass spiders (Agelenidae), and wolf spiders (Lycosidae) are frequently mistaken for brown recluses. However, none of these possess the specific violin marking and six-eye arrangement.
Life Cycle
Females produce several egg sacs containing around 50 eggs each during the warm months. Spiderlings molt multiple times as they grow, and adults can live for 2 to 4 years, making them relatively long-lived for araneomorph spiders.
Ecological Importance
They act as effective predators of household pests like roaches and silverfish, helping to naturally regulate insect populations within their range.
Conservation Status
Not evaluated by the IUCN, but populations are generally stable and robust throughout their native geographic range.
Interesting Facts
Brown recluse spiders can survive for months without food or water in extreme conditions. They are also known to tolerate very low temperatures in unheated buildings by entering a state of dormancy.
Photography Tips
Photograph from a safe distance using macro lenses or zoom. Capture a clear top-down view to display the cephalothorax violin marking, and ensure good lighting without flash glare to highlight diagnostic features.
Identified: 2026-08-09T21:46:46.401352