Loxosceles reclusa (brown recluse spider) 0.33"

Species Overview

Loxosceles reclusa, commonly known as the brown recluse spider, is a small terrestrial crevice-dwelling spider native to the south-central and Midwestern United States. Adults range from pale tan or yellowish-brown to reddish-brown. The abdomen is generally plain and covered with fine hairs, while the slender legs lack bold bands and prominent spines. Mature specimens usually display the familiar dark violin-shaped marking on the carapace, but this marking alone is not sufficient for identification. Brown recluses possess six eyes arranged in three widely separated pairs, and reliable identification requires the complete combination of physical characteristics.

In captivity, brown recluse spiders establish irregular silken retreats within narrow spaces and may remain almost completely motionless for extended periods. Activity occurs primarily after dark, when individuals remain positioned on or near the small silk network surrounding the retreat and wait for prey to enter striking range. Although the species is typically reluctant to bite and attempts to escape or remain concealed when disturbed, its venom is medically significant and can occasionally produce serious local or systemic effects. 

• Common Name: Brown recluse spider
• Native Range: South-central and Midwestern United States
• Life Habit: Terrestrial crevice-dweller
• Adult Size: Approximately 1.25–2 inches in diagonal leg span
• Lifespan: Males 2–3 years; females 3–5 years under optimal conditions
• Temperament: Reclusive and typically reluctant to bite; quick-moving when disturbed
• Care Difficulty: Easy; strict containment and cautious maintenance required due to medically significant venom

Loxosceles reclusa Care

Loxosceles reclusa adapts well to captivity when maintained in a secure, well-ventilated enclosure with a mostly dry substrate and a narrow retreat. Although its environmental requirements are straightforward, its small size and medically significant venom require careful containment and deliberate maintenance practices. Members of Loxosceles generally have difficulty scaling clean, smooth vertical glass or plastic, making smooth-sided containers useful for housing and maintenance. However, this limitation should never be relied upon as the sole means of containment because scratches, seams, ventilation openings, accumulated silk, and enclosure décor can provide footholds. Long tools should be used during all maintenance and rehousing, and a secure catch cup should be kept within immediate reach. Whenever possible, these procedures should be performed inside a larger secondary container capable of holding the spider if it escapes the primary enclosure.

• Enclosure: 1 oz condiment cup or similar for spiderlings, upgraded as needed with growth; 4” x 4” x 4” or similar for adults. Use a tightly locking lid and ventilation openings smaller than the spider’s carapace. 
• Substrate: A shallow layer of coconut fiber, peat moss, topsoil, sand, or a similar substrate is sufficient. Excessive substrate depth is not required. Provide a vertical or angled piece of cork bark positioned close to the enclosure wall to create a narrow, dark retreat.
• Temperature: 72–82°F. 
• Humidity: Low to moderate ambient humidity is generally sufficient. Approximately 25% of the substrate may retain slight moisture to provide a limited humidity gradient while allowing the remainder to stay dry. Avoid consistently damp substrate, condensation, and poorly ventilated conditions.
• Diet: Fruit flies, crickets, cockroaches, and other appropriately sized feeder insects.
• Feeding: Spiderlings can be offered appropriately sized prey once or twice weekly. Juveniles and adults are typically fed every 7–14 days, with feeding frequency adjusted based on prey size, growth rate, and the condition of the individual animal.
• Water: Provide water droplets on enclosure walls, cork bark, or other surfaces through regular light misting, lightly moistening the designated portion of substrate as needed. This species readily drinks from these surfaces. Do not saturate the substrate or mist the entire setup.
• Routine Maintenance: Remove uneaten prey, monitor moisture levels, and spot-clean when necessary.

Natural History

Loxosceles reclusa was described by Gertsch and Mulaik in 1940 from specimens collected in Texas. Its established range occupies a comparatively restricted portion of the central United States, extending roughly from central Texas north to southeastern Nebraska and east to southwestern Ohio and northern Georgia. Reports far outside this region frequently involve misidentified spiders or isolated specimens transported with household goods. In natural settings, brown recluses occupy dry, protected spaces beneath rocks, along rocky ledges, and under loose bark on dead trees. They also thrive within suitable human structures, where they shelter behind walls, beneath stored materials, inside boxes, and within other narrow, undisturbed spaces.

Despite the common name, brown recluse spiders are comparatively tolerant of conspecifics. Multiple individuals may occupy closely spaced retreats, and dense populations can develop wherever suitable shelter and prey are concentrated, including both natural and human-modified habitats. They are not truly social, however, and intraspecific predation can occur.

Brown recluse spiders exhibit strong attachment to established retreats. Mature females are particularly sedentary, while mature males wander more frequently while searching for mates. Research has also documented exceptional resistance to starvation and the ability to survive for several years under favorable captive conditions. Despite the species’ reputation, verified bites are uncommon relative to the number of spiders that may occupy an infested structure, and behavioral studies have documented a very low tendency to bite except when the spider is subjected to substantial pressure or trapped against the skin. Most suspected “brown recluse bites” are diagnosed without an identified spider, and many necrotic lesions have unrelated causes. This does not eliminate the genuine risk: confirmed bites can produce dermonecrosis, and uncommon systemic reactions may involve hemolysis and other serious complications. Any suspected bite should receive prompt guidance from Poison Control and appropriate medical evaluation.