Brown Recluse Spider, Fiddle-back Spider, Violin Spider
Loxosceles reclusa
Sicariidae (formerly Segestriidae or Loxoscelidae depending on revision), Order Araneae. Key family characteristics include six eyes arranged in distinct dyads.
Physical Description
The brown recluse has a uniform, velvety appearance due to tiny, fine hairs covering its body. It features a distinct violin-shaped marking on its cephalothorax, with the neck of the violin pointing backward toward the abdomen. The abdomen is oval, uniformly colored without stripes or distinct patterns.
Size Estimate
Body length typically ranges from 6 to 20 millimeters (about 1/4 to 3/4 inch), with a leg span of around 25 to 30 millimeters (1 inch). The specimen in the image appears small, likely a juvenile or a smaller male.
Coloration & Markings
Coloration ranges from light tan to dark brown. The defining marking is the dark violin shape on the dorsal side of the cephalothorax. The legs are uniformly light brown without any banding or distinct patterns.
Web Type
Does not build an aerial orb web. Instead, it constructs loose, irregular retreat webs usually in dark, secluded areas, utilizing sticky silken threads primarily for shelter rather than active prey capture.
Eye Arrangement
Uniquely possesses only six eyes arranged in three pairs (dyads): one pair in front and a pair on each side, leaving a characteristic gap between them. This distinguishes it from most spiders, which typically have eight eyes.
Leg Characteristics
Legs are long, slender, and uniformly colored without spines, bands, or distinct patterns. They are held somewhat flat against surfaces when resting.
Venom & Safety Information
Venom Information
Contains a potent necrotic venom primarily composed of the enzyme sphingomyelinase D, which destroys cell membranes and can cause localized tissue destruction (dermonecrosis).
Medical Significance
Medically significant. While many bites result in mild skin irritation or go unnoticed, some progress to necrotic lesions that heal slowly and may require medical treatment. Systemic reactions are rare but possible.
Safety Recommendations
Shake out shoes and clothing left on the floor, wear gloves when moving stored items in dark areas, and seal cracks and crevices in the home. Relocate individuals outdoors using a cup and card if found inside.
Habitat & Behavior
Habitat & Range
Native to the central and southern United States, ranging from midwestern states south to the Gulf Coast and west to Texas. Prefers dry, dark, undisturbed microhabitats such as woodpiles, basements, attics, closets, and behind furniture.
Behavior & Temperament
A nocturnal, timid hunter that actively forages away from its retreat at night. As the name suggests, it is highly reclusive and typically bites humans only when trapped against the skin (e.g., inside clothing or shoes).
Diet & Prey
Feeds primarily on small insects such as cockroaches, crickets, and other soft-bodied arthropods. It subdues prey using venom injected via its fangs.
Seasonal Activity
Most active during spring and summer months when mating occurs and foraging increases. In heated indoor environments, they can remain active year-round.
Description
The brown recluse is a famously misunderstood synanthropic spider known for its violin-shaped marking and potent necrotic venom. While reclusive and non-aggressive by nature, its tendency to inhabit human dwellings warrants respectful caution.
Key Features
Six eyes arranged in three pairs; dark violin-shaped marking on the cephalothorax; uniform brown coloration with no banding on the legs; lack of distinct abdominal patterns.
Similar Species
Cellar spiders (Pholcidae), funnel-weaver spiders (Agelenidae), and pirate spiders (Mimetidae) are often mistaken for the brown recluse. They can be distinguished by having eight eyes and prominent body or leg patterns.
Life Cycle
Females produce several egg sacs containing around 50 eggs each during the warmer months. Spiderlings go through multiple molts as they mature. Lifespan can reach 1 to 3 years.
Ecological Importance
Acts as an effective predator of household and agricultural insect pests, helping to naturally regulate arthropod populations.
Conservation Status
Not evaluated by the IUCN, but populations are secure and abundant throughout their native geographic range.
Interesting Facts
Brown recluses can survive for months without food or water. They are remarkably resilient in indoor environments where humidity is low.
Photography Tips
Use macro lenses for close-up shots focusing on the eye arrangement and the dorsal violin marking. Maintain a safe distance and use diffused natural light or an external ring flash.
Identified: 2026-10-15T11:19:33.800665