Brown Recluse, Violin Spider, Fiddle-back Spider
Loxosceles reclusa
Family Sicariidae (Six-eyed Sand Spiders and Recluses), Order Araneae
Physical Description
A medium-sized spider with a relatively flat cephalothorax and an oval-shaped abdomen. The body is covered in fine, short hairs rather than spines. They are known for a characteristic dark violin or fiddle-shaped marking on the top of the cephalothorax.
Size Estimate
Body length is typically 6-20 mm (1/4 to 3/4 inch). The specimen in the image appears to be an adult, with a total leg span approximately the size of a U.S. quarter (around 1 inch or 25mm).
Coloration & Markings
Uniformly light tan to dark brown or grayish-yellow, without any stripes or bands on the legs. The primary identifying mark is a dark brown violin-shaped pattern on the cephalothorax (the 'neck' of the violin points toward the abdomen).
Web Type
They build irregular, flat, grayish-white silk webs that appear 'messy' or tangled. These are use as retreats rather than for snaring prey. Webs are typically found in dark, undisturbed areas like woodpiles, sheds, closets, or behind furniture.
Eye Arrangement
Distinctive arrangement of six eyes (unlike most spiders which have eight) arranged in three pairs (dyads) in a semi-circle across the front of the head.
Leg Characteristics
Long, slender, and uniformly colored. Crucially, they lack prominent spines (macrosetae) on the legs, having only very fine hairs. When at rest, the legs are often sprawled out flat.
Venom & Safety Information
Venom Information
Possesses a necrotic venom containing the enzyme sphingomyelinase D. The venom can cause local tissue death (necrosis) in some cases, though many bites result only in minor swelling and redness.
Medical Significance
Medically significant. While most bites heal without complications, some can result in a necrotic ulcer (loxiscelism) or, rarely, systemic symptoms (visceral loxoscelism) like fever or chills. Seek medical attention if a bite is suspected.
Safety Recommendations
Shake out clothing and shoes left on the floor. Wear gloves when moving storage boxes or wood. To relocate, use a jar and stiff paper to trap the spider without touching it.
Habitat & Behavior
Habitat & Range
Commonly found in the Central and Midwestern United States. They prefer dark, dry, undisturbed locations such as attics, crawlspaces, basements, and inside storage boxes or folded clothing.
Behavior & Temperament
Reclusive and shy by nature (hence the name). They are nocturnal hunters that wander at night to find prey. They are not aggressive and generally only bite when pressed against skin, such as when trapped in clothing or bedding.
Diet & Prey
They are active hunters that feed on a variety of soft-bodied insects like crickets, cockroaches, and silverfish. They may also scavenge on dead insects.
Seasonal Activity
Maximum activity occurs in the spring and summer months (March through October). During winter, they remain largely dormant in wall voids or insulated areas.
Description
The Brown Recluse is one of the most misunderstood and frequently misidentified spiders in North America. An understated, uniformly colored spider, it thrives by avoiding human interaction. Despite its fearsome reputation, it plays a vital role as an apex predator of household pests.
Key Features
Fiddle-shaped marking on the head; six eyes in three pairs; sandy-brown uniform color; lack of leg bands or thick spines.
Similar Species
Often confused with Tegenaria (House Spiders), Wolf Spiders (Lycosidae), or Southern House Spiders (Kukulcania hibernalis). These other species usually have eight eyes, striped legs, or lack the violin mark.
Life Cycle
Females produce 1-5 egg sacs containing about 40-50 eggs each during summer months. Spiderlings take about a year to reach maturity. Adults can live for 1 to 2 years, and are remarkably resistant to long periods of starvation.
Ecological Importance
Highly effective at controlling populations of domestic pests like cockroaches and silverfish within human structures.
Conservation Status
Not evaluated by the IUCN; populations are stable and common throughout their native range.
Interesting Facts
The 'violin' marking is most prominent in adults and can be faint in juveniles. They can survive for months without food or water.
Photography Tips
A clear, well-lit top-down photo of the cephalothorax is essential to see the violin mark and the three pairs of eyes. Avoid macro shots that are blurry, as fine hairs are a key ID trait.
Identified: 2026-05-21T01:38:27.811655