Brown Recluse Spider Range

Table of Contents

What are Brown Recluse Spiders?

The brown recluse spider is most often seen in the United States’ Midwest and Southeast, and is commonly recognized by a dark brown violin shape on its back.

Because it prefers to live in warm, dry, and dark places such as woodpiles, basements, and closets, this species is well recognized for its “secretive” behaviors.

When a hand or foot enters into a shoe, garment, or box in the attic or basement where a brown recluse has made its home, this arachnid bites, usually unintentionally.

It is crucial to keep an eye on the individual who was bitten since their bites may take three or more hours to form and up to three weeks to heal. Children, the elderly, and people with previous medical conditions are particularly susceptible to the brown recluse venom, which may cause severe allergic responses.

The color of the brown recluse, also known as the fiddleback/violin spider, and its reclusive habits (the dark violin/fiddle-shaped mark on top of its chest) are what give it its common names.

Southern Europe, temperate Africa, and North, Central, and South America are all home to brown recluse spiders.

Brown recluse spiders are most prevalent in the Midwest and Southeast regions of the United States. Six of the 11 identified species are of public health concern.

A recluse spider with necrotic venom, the brown recluse, Loxosceles reclusa, Sicariidae (previously classified as a family “Loxoscelidae”) Their bites may occasionally necessitate medical care, similar to those of other recluse spiders.

Together with the black widow and the Chilean recluse, the brown recluse is one of three spiders in North America whose venom is medically relevant.


The average length of a brown recluse spider is 6 to 20 millimetres (0.24 to 0.79 in). They range in color from white to dark brown or blackish gray, although being light to medium brown.

The color of the cephalothorax and abdomen is not always the same.

The fiddleback spider, brown fiddler, or violin spider is a nickname for these spiders because of the black line that extends from their cephalothorax to the rear of the spider, resembling a violin with its neck pointing backwards.

The bite of the brown recluse spider is infamous for being venomous. It is the most frequent and widely distributed of the brown spiders, however it is only found in the southern and central United States.

According to MedlinePlus, a service of the National Library of Medicine, people bitten by brown recluse spiders should ice the wound and seek urgent medical care. Brown recluse spider bites may cause necrotic (rotting) skin lesions and serious symptoms or even death in certain persons, particularly children.

Nevertheless, Rick Vetter, a former research associate of entomology at the University of California, Riverside (opens in new tab), wrote on the institution’s website that “roughly 90% of brown recluse wounds are not medically significant and heal very nicely, frequently without medical care or treatment.”

People with minor bites who seek urgent care often recover quickly after cleaning the wound and following the RICE technique — rest, ice, compression, and elevation.


It may be difficult to locate the brown recluse spiders’ dens since they are solitary and secretive.

Brown recluse spiders may be found in almost any dark, undisturbed corner. These spiders may be found beneath rocks and logs in their natural environment.

Brown recluse spiders, on the other hand, prefer human-altered settings to natural ones.

Boxes, clothes, shoes, furniture, bedding, rubber tires, and other dry and dark warm places are all suitable habitats for brown recluse spiders. Closets, basements, and cellars are some of the most common storage spaces.

It is more common to find many of these spiders than to find just one, due to their high reproductive potential.


Habits and Development

Brown recluse spiders prefer to dwell under rocks, logs, woodpiles, and other debris outside in the wild. Living indoors with humans is also a favored environment for spiders.

They can endure winters in unheated basements and stifling summer heat in attics for many months without food or water, proving to be tough enough. During the night, the brown recluse looks for live or dead insects to catch.

Suspended webs strung along walls, corners, ceilings, outdoor vegetation, and other exposed areas are virtually usually connected with other kinds of spiders. It does not use a web to catch food.

Harmless cobweb or cellar spiders are frequently responsible for such webs in homes.

Spiders such as the cobweb or basement varieties may be considered beneficial in that they eat other pests (including brown recluses), despite being sometimes seen as a bother.


Brown recluse spiders prefer to hides in dark, secluded places during the day. They use irregular webbing to make their egg sacs and line their daytime retreats with it.

While males and older juveniles are more mobile and tend to travel farther, adult female recluses seldom venture far from their retreat.

As a result, they are more likely to bite people when they get trapped against the skin at night, especially in shoes, clothes, or bedding.

Brown recluse spiders may sometimes be seen scurrying on floors, walls, and other open areas during the day.

Hunger, overpopulation, pesticide application, and other factors may all contribute to such behavior.

1/3-inch diameter off-white silken egg sacs contain approximately 40-50 eggs. Before becoming adults, the little spiders grow in size, molting five to eight times.

Molted (shed) brown recluse skins have a distinct outstretched look that may be used to confirm infestation.


The average lifespan of brown recluse spiders is 2 to 4 years when they reach adulthood. In a lifetime, females may lay up to 5 egg sacs. The quantity of spiders in a residence may vary from one or two to hundreds.

Brown recluse spider Geographic Range

From Nebraska to Ohio, and from Texas to Florida, the brown recluse spider’s natural range (Loxosceles reclusa) is currently known. Unlike other pest spiders like the brown widow or yellow sac spider, it is indigenous to the United States.

The center section of their range, where hundreds or even thousands may be found in a single structure, has the highest concentrations of recluses.

Nonetheless, brown recluse bites are most typically the consequence of other medically related illnesses, such as bacterial skin infections, despite claims that they may be endemic in states outside of these areas.

Recluses may be transported due to their tendency to hide in dark places, such as boxes. Recluses were accidentally brought in through relocated objects, according to documented cases of solitary buildings outside their recluse range.

From southeastern Nebraska through southern Iowa, Illinois, and Indiana to southwestern Ohio, this species’ known range is roughly south of a line.

It can be found from central Texas to western Georgia and north to Kentucky in the southern United States.

The brown recluse spider has not established itself in California or anywhere outside its natural range, despite rumors to the contrary.

Several other Loxosceles species native to the southern United States, particularly California, may resemble the brown recluse but human-recluse encounters are uncommon since those species’ natural habitats are outside of dense human populations.

In a nationwide study where spiders were submitted by people thinking they were brown recluses, only 1 out of 581 was a brown recluse (compared to specimens submitted from Missouri, Kansas, and Oklahoma, where between 75% and 90% were brown recluses).

The genus Titiotus, whose bite is thought to be harmless, was the most common spider submitted from California as a brown recluse in this study.

Physicians, pest control operators, and other non-expert authorities have been known to incorrectly identify spiders in similar research, which revealed that they were often misidentified by physicians.

Despite the fact that brown recluses are not found in the Western United States, doctors in the region frequently identify “brown recluse bites,” giving rise to the misconception that they do.

Spiders have been found in places where they do not have any known established populations throughout the last century; these spiders may be transported quite simply, although the absence of established populations outside of their native range suggests that such movement has not resulted in the colonization of new regions after decades.

It’s worth noting that isolated instances of brown recluses (e.g., in a single structure in Florida) may arise, but they don’t spread and are readily eliminated; these isolated instance populations may develop (but just in a few cases).

In 2014, a man in Thailand was claimed to have died from a brown recluse bite, and the spider has also garnered several sensationalized media reports of bites where these spiders are not found (and no specimens were found).

The closeness between L. and L. has led to many misidentifications and erroneous geographic data. The Mediterranean recluse (Loxosceles rufescens), a related imported species, is the only one.

The two species are nearly unmistakable from one another, and misidentifications are common, making it difficult to tell which recluses reports refer to which species.


According to Vetter(opens in new tab), brown recluse spiders (Loxosceles reclusa) are found in Kansas, Oklahoma, Texas, Louisiana, Arkansas, Missouri, Mississippi and parts of Georgia through Tennessee through Kentucky.

According to Vetter(opens in new tab), if you don’t reside in those areas, “it is EXTREMELY UNLIKELY that you have a recluse spider.”

The continental United States is home to eleven species of Loxosceles, four of which are known to be hazardous to people.

Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Mississippi and Missouri are the sixteen states where brown recluse spiders have been discovered.

Arizona, California, the District of Columbia, Florida, North Carolina, and New Jersey have also reported isolated occurrences.

Wyoming, as well as Washington and Idaho. Brown recluse spiders are seldom seen in Pennsylvania, however they may be brought from another state if they are typically found.

A closely related species, the Mediterranean recluse, Loxosceles rufescens, was brought from southern Europe. It has locations in the Northeast, as well as Penn State’s steam tunnels.

Despite their lengthy stay in the Penn State steam tunnels, these spiders have never bitten any workers or students. The brown recluse spider’s bites may cause mild symptoms, unlike the severe symptoms caused by these spiders.

Brown recluse spider Bite

Because of the presence of sphingomyelinase D toxin in its venom, Loxosceles reclusa (like all members of the Loxosceles genus) may cause delvenomation via uncate chelicerae-type fangs.

There is no dermonecrosis in the majority of bites. Nevertheless, certain brown recluse injuries may cause dermonecrotic loxoscelism, as well as more severe cutaneous (skin) or viscerocutaneous (systemic) symptoms.

Skin necrosis was seen 37% of the time in one study of brown recluse bite wounds, and 14% of the time in cases with systemic illness.

Bites in these situations caused cutaneous and viscerocutaneous symptoms that are similar to those experienced by other members of the genus Loxosceles (loxoscelism). Bites may also cause hemolysis, which is the destruction of red blood cells in very rare circumstances.

The brown recluse spider is generally calm, and Brown Recluse Spider Bites are uncommon. This is in line with the species’ particular name of reclusa (recluse).

Despite numerous encounters with the spiders, none of the four people who had lived there for years were ever bitten by them in 2001, when over 2,000 brown recluse spiders were removed from a severely infested residence in Kansas.

When pressed against the skin, such as when caught in clothes, shoes, towels, bedding, or work gloves, the spider usually bites only.

After putting on clothing or shoes that had not been worn recently or that had been sitting on the floor for many days, many human casualties claim to have been bitten. Most fabrics are unlikely to be penetrated by the brown recluse’s fangs.


Since the venom spreads throughout the body in minutes, systemic effects may appear before necrosis in both types of loxoscelism. Systemic loxoscelism may affect children, the elderly, and those who are sick or crippled.

Nausea, vomiting, fever, rashes, and muscle and joint pain are some of the most common symptoms that people have. Hemolysis, low platelet counts, blood clotting throughout the body, organ damage, and even death are all rare side effects of such bites.

Children under the age of seven or people with a compromised immune system are most likely to die.

Cutaneous symptoms are more common than systemic symptoms, despite the fact that most brown recluse spider bite injuries do not cause any symptoms.

A necrotizing ulcer develops as a consequence of soft tissue destruction in such circumstances, and it may take months to heal.

Within 2 to 8 hours, these bites typically become painful and itchy. The necrosis worsens over the following few days, and pain and other local complications worsen 12 to 36 hours after the bite.

The injury might expand to 25 cm (10 inches) in size over time. Gangrene develops in the injured tissue, which sloughs off over time. This is a good example of an L. While the typical yield is less, reclusa venom may generate somewhat more than 0.1 microliters.

How is a brown recluse spider bite treated?

The severity of the bite determines how it is treated. Bites that meet the following criteria are classified as such:

-To avoid the development of open sores, refrigerate the bitten region, raise the bitten region, and refrain from moving it.
-Treatment includes removing the dead skin from an open wound (ulcer) and causing necrosis in the wound. This might necessitate additional treatment and the use of skin grafts to replace dead skin.

For tissue damage caused by a spider bite, hyperbaric oxygen treatment may be used.

Medicines that may be used include:

Acetaminophen (Tylenol) and non-steroidal anti-inflammatory drugs (NSAIDs) are examples of pain medications. Naproxen (Aleve) and ibuprofen (Advil, Motrin) are two examples of NSAIDs. When it comes to medication, be cautious.

Because of the risk of Reye syndrome, do not give aspirin to anyone younger than 18. Read and follow all instructions on the label.

-To relieve itching, antihistamines, such as non-drowsy loratadine (Claritin) or diphenhydramine (Benadryl), may be used.

-Antibiotics, if an infection is present.

In Canada and the United States, there is no medicine to treat brown recluse spider venom.