Loxosceles reclusa
(Brown Recluse)

Taxonomic Hierarchy

• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Arachnida
• Order: Araneae
• Suborder: Araneomorphae
• Family: Sicariidae
• Genus: Loxosceles
• Species: Loxosceles reclusa

Common Name (AAS)

Brown Recluse

Other Common Names

Brown Spider, Violin Spider, Six-eyed Brown Spider, Fiddle-back Spider

Author

Willis J. Gertsch & Stanley Mulaik, 1940

Primary Colors

Sightings Overview

There have been 84 confirmed sightings of Loxosceles reclusa (Brown Recluse), with the most recent sighting submitted on August 1, 2023 by Spider ID member bacaleegamer. The detailed statistics below may not utilize the complete dataset of 84 sightings because of certain Loxosceles reclusa sightings reporting incomplete data.

• Web: 4% of the time, Loxosceles reclusa spiders are sighted in a spider web (Sample size: 84)
• Sex: 3 female and 37 male.
• Environment: Loxosceles reclusa has been sighted 4 times outdoors, and 80 times indoors.
• Outdoors: Man-made structure (3). Ground layer (1).

Location and Range

Loxosceles reclusa (Brown Recluse) has been sighted in the following countries: United States.

Loxosceles reclusa has also been sighted in the following states: Alabama, Arkansas, Illinois, Indiana, Kansas, Kentucky, Mississippi, Missouri, Oklahoma, Tennessee, Texas, Virginia.

Seasonality

Loxosceles reclusa has been primarily sighted during the month of May.

• January: 3
• February: 9
• March: 4
• April: 17
• May: 27
• June: 17
• July: 1
• August: 1
• September:
• October: 3
• November: 1
• December: 1

Additional Remarks

• People mistake all sorts of (typically innocuous) spider species for the “brown recluse.” Especially male Kukulcania hibernalis, species of Cheiracanthium and, in California in particular: Metaltella simoni and spiders in the genus Titiotus.
• This spider’s venom contains sphingomyelinase D, a necrosis-causing enzyme.
• This is a medically significant species: venom is potentially dangerous to humans. Reactions can vary from “unremarkable” (little, if any, damage and are self-healing) and “mild” (redness and itching, but usually self-healing) to “dermonecrotic” (a necrotic skin lesion that requires medical intervention) or, very rarely “systemic” (affecting the vascular system and potentially fatal). The potential for bites is slim, and can be largely avoided by taking simple precautions, and the majority of verified cases fall into the first two categories (unremarkable or mild). Most importantly, many other medical conditions can produce the skin lesions so often wrongly attributed to Loxosceles or other types of spiders. Please consult Rick Vetter’s 2008 article for a list of these. Misdiagnosis can lead to worse problems than a mere spider bite (if the actual cause is MRSA, for example).
• Less than 10% of bites are considered serious or medically significant.
• This species is not social (they do not share their webs or help each other catch food, etc), but they are incredibly tolerant of one another and can be found in very high numbers within a single location. The rule of thumb is often: “where there is one, there are many.”
• A single female produces about 3 egg sacs in her lifetime, each filled with roughly 50 individual eggs (Vetter 2008). Some of the eggs may be infertile and some may be eaten by spiderlings from previous egg sacs, so only about half of them will actually end up “hatching” (Edwards 2001).