What Does A Brown Recluse Spider Web Look Like?

What does a brown recluse spider look like?

A brown recluse may be brown or tan, with a violin-shaped area on the front half of its body. The neck of the violin points toward the spider’s belly.

It may be bigger than other spiders, from 1/4-inch to 3/4-inch. Its long legs make it seem even larger.

A brown recluse spider has six eyes: Two in front, and two more on each side of its head.

They’re found mostly in the Midwest and South. The spider favors indoor spaces, like attics, garages or dark closets. Outdoors, it hides in out-of-the-way places — under logs, beneath porches, or within piles of rocks.

Reviewed by Jennifer Robinson on December 16, 2018

U.S. Department of Labor: “Brown Recluse Spider.”

CDC: “Venomous Spiders,” “Types of Venomous Spiders.”

Mayo Clinic: “Spider Bites Overview,” “Spider Bites Diagnosis,” “Spider Bites Symptoms and Causes,” Spider Bites: Preparing for Your Appointment,” “Spider Bites Treatment.”

Nemours Foundation: “Bug Bites and Stings.”

University of California: “Brown Recluse and Other Recluse Spiders.”

U.S. Department of Labor: “Brown Recluse Spider.”

CDC: “Venomous Spiders,” “Types of Venomous Spiders.”

Mayo Clinic: “Spider Bites Overview,” “Spider Bites Diagnosis,” “Spider Bites Symptoms and Causes,” Spider Bites: Preparing for Your Appointment,” “Spider Bites Treatment.”

Nemours Foundation: “Bug Bites and Stings.”

University of California: “Brown Recluse and Other Recluse Spiders.”

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Brown Recluse Spider Web

Many spiders are builders of spiral, wheel-shaped, symmetrical webs. Conversely, the web of a brown recluse spider is irregular and loosely constructed. Like other spiders, brown recluse spiders build their webs from protein-based silks, released from organs known as spinnerets. The strands of the brown recluse web are off-white in color.

The web of the brown recluse spider is not used to trap prey, as brown recluses actively hunt for food. The purpose of the recluse’s web is to serve as retreat.

Whereas other spiders weave webs in strategic locations in order to capture prey, the brown recluse spins its web in undisturbed locations. These webs are commonly found in dry, dark areas such as attics, basements, cellars, closets, crawlspaces and ductwork. Brown recluses are also known to spin their webs in storage boxes, shoes, clothing, linens, papers, tires and beneath undisturbed furniture. Outside, they can be found under rocks, logs and lumber, as well as in barns, storage sheds and garages.

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Brown Recluse Web Identification

The brown recluse spider is an accomplished recluse. Unfortunately, this can make brown recluse spider web identification difficult. But if you are trying to decide whether or not you have one of these spiders lurking somewhere in your home, using a web for identification has some advantages. Ask yourself the following two questions to decide if the webs in your home are brown recluse webs or not.

Are there any insects caught in the spider web?

Brown recluses are hunting spiders. This means that they chase after prey instead of building webs and lying in wait. Large webs that have been built in flat sheets or between branches of leaves outside most likely belong to web building spiders. Orb weavers are especially common around the house and build prominent webs in garden areas. Comb-footed spiders are common in the home and build traditional cobwebs that look messy and tangled. These types of open-spaced webs are most likely not brown recluse spider webs.

Has it been built in a crevice?

While they may hunt for their prey, brown recluses still build webs. However, the brown recluse web is used mostly for retreat and to lay eggs. For these reasons, you will mostly find brown recluse spider webs in undisturbed locations. This includes dry, dark areas in basements and beneath furniture or storage boxes. These spiders also sometimes build webs in old shoes or clothing items that have not been worn in a while. This can be dangerous and lead to humans getting bit by the spider.

While brown recluse web identification can be a challenge, finding a web is often the first sign of a spider. If you are concerned about spiders in your home, contact a pest management professional.

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Brown Recluse Spider’s Silk Is Strong and Really Strange

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Brown Recluse Spider’s Silk Is Strong and Really Strange

One of the most feared spiders in North America might soon be known for something other than its notoriously nasty venom: really strange silk.

See also:  What Does A Spider Bite Look Like On A Toddler?

The brown recluse spider spins a silk unlike any other produced by known arachnids or insects. Instead of being round, the recluse silk fibers are flat and extremely thin, like a silky nanoribbon. And they’re spotted with tiny spherical dots, a team of scientists reports today in Advanced Materials.

“It’s so distinct from the traditional silks many of us look at,” said David Kaplan, a biopolymers engineer at Tufts University who was not involved in this study. “How you spin something with that shape is not trivial. The mechanism is something worth looking at in detail, with broad implications.”

Brown recluse spiders (Loxosceles sp.) are smaller than a quarter, and pretty good at keeping out of sight. Preferring the solitude offered by a dark basement corner, the underside of your couch, or a woodpile, brown recluses venture out most frequently at night. Many brown spiders are mistaken for recluses, which – unlike most – have only six eyes, fewer than the usual eight. They also have a violin-shaped mark on their backs, spin an irregular, messy web near their secluded shelters, and have small fangs that are incapable of biting through fabric (but can break through thin skin).

Accidentally coming into bare-skinned contact with a brown recluse – think, rolling over on an unexpected bed-mate or rudely inserting a foot into a shoe-borne hiding place – can result in a bad bite. The spiders’ venom contains a protein that attacks cell membranes, killing tissues and leading to large, necrotic ulcers that sometimes send people to the emergency room wondering what carved a hole into their limbs.

Up until now, that’s been pretty much what the brown recluse is known for. But this new, detailed examination of recluse silk could change that.

First, scientists harvested silk from several spiders kept in a lab at The College of William and Mary. To do this, the team either collected strands the spiders had laid down in their vials, or reeled it from the spiders themselves – individuals from the species Loxosceles laeta, the Chilean brown recluse. Closely related to their U.S. counterpart (L. reclusa), the Chilean spiders are fairly well established in southern California, and once moved into the basement of Harvard’s Museum of Comparative Zoology.

Though it might seem somewhat risky, raising and handling recluses wasn’t too tricky, said materials scientist and study coauthor Hannes Schniepp. And as far as lab animals go, the spiders are fairly low-maintenance.

“These are amazing creatures,” Schniepp said. “They don’t need a lot of food. They don’t need a lot of air. When they get one cricket or one animal, they can last for months.”

Once Schniepp and his colleagues had the silk in hand, they used electron and atomic force microscopy to study the silk’s structure on a very fine scale. To their surprise, they found that the brown recluse silk was much thinner than other spider silks, between 40 and 80 nanometers thick. Most spider silk is 20 times thicker than this.

And it was flat, like a ribbon, instead of rounded like a strand of spaghetti. What’s more, the fibers were polka-dotted: They had small, nano-sized bumps at relatively equal intervals.

Mechanical tests, using a modified atomic force microscope, revealed how strong the silk is. More testing suggested it could stretch to 30 percent longer than its original length without snapping. So, brown recluse silk is comparable in strength to the best-studied silks (though much thinner), and by weight is as tough as Kevlar – but much more flexible.

“All the G.I.s in Afghanistan that are wearing bulletproof vests and helmets, they all have Kevlar fibers in them,” Schniepp says. “It’s quite amazing that some of the spiders can outperform these materials just by eating a few crickets.”

The team suggests that the flat shape of brown recluse spinnerets produces the oddly shaped silk, rather than the structure reflecting weird proteins in the silk itself. They think the fiber’s flatness and nanodots help the silk to be super-sticky. «It hugs the surface, so it can form very strong bonds,» said coauthor Fritz Vollrath, of the University of Oxford. «It’s very strong, and only a few molecules thick.»

Now, the team is working on learning more about the enigmatic silk, its function, and how the clues it offers about silk structure in general, perhaps with an eye toward synthetic applications.

“It’s really peculiar,” Schniepp said. “Is there really a purpose for the thinness of this fiber, or is this just a coincidence or an accident of evolution?”

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Brown Recluse Spiders

Facts, Identification & Control

Latin Name

Appearance / Identification


Brown Recluse Spider

How Did I Get Brown Recluse Spiders?

Like many spiders, the brown recluse spider likes to stay secluded in dark corners of places that are rarely disturbed or cleaned. Inside locaations such as voids between and under kitchen cabinets, storage areas and basements inside houses can provide plenty of areas for these pests to hide. Outside these spiders may inhabit sheds, barns and garages and may unknowingly be brought inside a home when moving stored items inside. The abundance of prey insects can lure a brown recluse spider inside the house, as well as provide a sustainable source of food should they get inside a home.

How Serious Are Brown Recluse Spiders?

The pests lay up to five egg sacs with as many as fifty eggs in each. This can quickly escalate an infestation. While they typically refrain from attacking humans, brown recluse spiders will bite if provoked. This often occurs when people step on the pests or roll on them while sleeping. Bites can result in lesions, nausea, and fever.

How Do You Get Rid of Them?

The Orkin Man™ is trained to help manage brown recluse spiders. Since every building or home is unique, your Orkin technician will design a special program for your situation.

Keeping spiders out of homes and buildings is an ongoing process, not a one-time treatment. Orkin’s exclusive A.I.M. solution is a continuing cycle of three critical steps — Assess, Implement and Monitor.

See also:  Wolf Spider What Do They Eat?

The Orkin Man™ can provide the right solution to keep spiders in their place. out of your home, or business.

Signs of a Brown Recluse Spider Infestation

The most likely sign of recluses are sightings of the spider.

Behavior, Diet & Habits

Brown recluse spiders dwell in many of the same dark, sheltered places as black widows. They can be found in homes, barns and basements. Webs tend to appear disorganized and are built most commonly near ground level. The spider is a hunter, so the web is not intended to catch prey but instead roams around searching for prey. The brown recluse is found in the central southern part of the U.S., from Texas to the western most part of Florida.

Brown recluse spiders are shy and rarely bite unless provoked. Bites usually go unnoticed until effects manifest a few hours later. Most bites become red and fade away, but in uncommon cases necrosis or tissue damage can occur. A medical professional should be consulted if there are medical concerns.

More Information

Although urban myth purports that they are found throughout the U.S., studies have shown otherwise. Brown recluse spiders are endemic only to the American South and Midwest. Relocation of the brown recluse can occur in boxes or items moved from its native range. These usually are isolated events and do not result in an entire area becoming infested.

Many conditions are mistakenly diagnosed as brown recluse spider bites, including Lyme disease, diabetic ulcers, reactions to medication and bacterial infections.

Due to misinformation and fright, many people identify harmless spiders as brown recluses. They are also referred to as fiddleback spiders due to a distinctive marking on the thorax, which resembles a violin. Brown recluses have uniformly colored legs and abdomens; so any spider exhibiting distinct color variations and patterning on the legs or abdomen is not a brown recluse.

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Brown Recluse Spider

ENTFACT-631: Brown Recluse Spider | Download PDF | En Español

by Michael F. Potter, Extension Entomologist
University of Kentucky College of Agriculture

Many types of spiders live around homes and buildings. Most are harmless, and many are beneficial given they prey upon other nuisance insects, like mosquitos or flies.

One spider found in Kentucky and much of the Midwest that is potentially dangerous is the brown recluse. It is sometimes referred to as the ‘violin’ or ‘fiddleback’ spider because of the violin-shaped marking on its dorsum. Although brown recluse spider bites are rare, the venom can sometimes cause serious wounds and infestations should be taken seriously.


Fig. 1: Brown recluse spiders often have a fiddle-shaped marking.

Distribution and Diagnosis

The brown recluse spider, Loxosceles reclusa, is found throughout the south central and Midwestern United States. Infestations in Kentucky are more common as one travels westward. Other species of Loxosceles spiders occur in the southwestern U.S. and southern California, but the brown recluse is the most notable and widespread. Recluse spiders are rare outside their native range. In general, these spiders are widely over-reported and less common than perceived. Occasionally, one or a few spiders may be transported to a non-native area in boxes or furnishings, but infestations seldom become established.


Fig. 2: Distribution of the brown recluse spider (dark shading) and other species of Loxosceles spiders in the U.S. (light shading) (adapted from distribution map of R. Vetter, Univ. Calif. Riverside).

Though variable in size, adult brown recluse spiders with legs extended are about the size of a U.S. quarter. Coloration ranges from tan to dark brown, and the abdomen and legs are uniformly- colored with no stripes, bands or mottling. The legs are long and thin and lack conspicuous spines. For laypersons, the most distinguishing feature of a brown recluse is a dark violin-shaped mark on its back, with the neck of the violin pointing toward the rear (abdomen) of the spider. This feature is consistent in adult brown recluses, but sometimes less obvious in younger spiders.


Fig. 3: The banding on the legs of this wolf spider is one indication that it is not a brown recluse.

A more definitive diagnostic feature is the eye pattern — brown recluses have a semi-circular arrangement of six eyes (three groups of two) while most other spiders have 8 eyes. Seeing this feature requires a good quality hand lens. Many harmless brown spiders are mistaken for the brown recluse, so it is prudent to have specimens confirmed by an entomologist or knowledgeable pest control firm.


Fig. 4: Brown recluse spiders have three pairs of eyes, arranged in a semi-circle.

Habits and Development

In nature, brown recluse spiders live outdoors under rocks, logs, woodpiles and debris. The spider is also well adapted to living indoors with humans. They are resilient enough to withstand winters in unheated basements and stifling summer temperatures in attics, persisting many months without food or water. The brown recluse hunts at night seeking insect prey, either alive or dead. It does not employ a web to capture food — suspended webs strung along walls, corners, ceilings, outdoor vegetation, and in other exposed areas are almost always associated with other types of spiders. In homes, such webs are often produced by harmless cobweb or cellar spiders. While sometimes considered a nuisance, spiders like the cobweb or cellar varieties prey upon other pests (including brown recluses), and in this sense could be considered beneficial.


Fig. 5: Cobweb spiders (left) and cellar spiders (right) often build webs in homes, but are harmless.

During daylight hours, brown recluse spiders typically retreat to dark, secluded areas. They often line their daytime retreats with irregular webbing, which is used to form their egg sacs. Adult female recluses seldom venture far from their retreat, whereas males and older juveniles are more mobile and tend to travel farther. Consequently, they are more likely to wander into shoes, clothing or bedding at night and bite people when they inadvertently become trapped against the skin. At times, brown recluse spiders will be seen during daylight hours crawling on floors, walls and other exposed surfaces. Such behavior can be triggered by hunger, overcrowding, pesticide application, or other factors.

About 40-50 eggs are contained within 1/3-inch diameter off-white silken egg sacs. The tiny emerged spiders gradually increase in size, molting five to eight times before becoming adults. The molted (shed) skins of the brown recluse have a distinct outstretched appearance and can be useful in confirming infestation.


Fig. 6: Shed skins of a brown recluse spider

Brown recluse spiders mature in about a year and have an average lifespan of 2 to 4 years. The females produce up to 5 egg sacs in a lifetime. Infestation levels in homes vary greatly, ranging from one or a few spiders to several hundred.

Bites and Medical Significance

Like other spiders, the brown recluse is not aggressive. It is quite common, in fact, to live in a building that is heavily infested and never be bitten. Most bites occur in response to body pressure, when a spider is inadvertently trapped against bare skin. Some people are bitten when they roll over a brown recluse in bed. Other bites occur while moving stored items or putting on a piece of clothing that a spider has chosen for its daytime retreat. Brown recluse spiders have very small fangs and cannot bite through clothing.

The initial bite is usually painless. Oftentimes the victim is unaware until 3 to 8 hours later when the bite site may become red, swollen, and tender. The majority of brown recluse spider bites remain localized, healing within 3 weeks without serious complication or medical intervention.

In other cases, the victim may develop a necrotic lesion, appearing as a dry, sinking bluish patch with irregular edges, a pale center and peripheral redness. Often there is a central blister. As the venom continues to destroy tissue, the wound may expand up to several inches over a period of days or weeks. The necrotic ulcer can persist for several months, leaving a deep scar.

See also:  What Do Yellow Garden Spiders Eat?

Infrequently, bites in the early stages produce systemic reactions accompanied by fever, chills, dizziness, rash or vomiting. Severe reactions to the venom are more common in children, the elderly, and patients in poor health. Persons bitten by a brown recluse spider should apply ice, elevate the affected area, and seek medical attention immediately.

Medical Misdiagnosis

Spider bites are difficult to diagnose, even by physicians. Contrary to popular belief, it is difficult to diagnosis a brown recluse spider bite from the wound alone. Many medical conditions mimic the necrotic-looking sore from a recluse bite, including bacterial and fungal infections, diabetic and pressure ulcers, and gangrene. Several misdiagnoses have arisen from outbreaks of drug-resistant infections by Staphyloccus aureus (commonly referred to as a Staph infection). That bacterium produces painful skin lesions that resemble recluse bites, and can run rampant in close living quarters such as hospitals, camps, barracks, and correctional facilities. Similar-looking lesions can also be caused by other types of insects and arthropods.


Fig. 7: Many medical conditions are mistaken for brown recluse bites.
The wound on the left is from a recluse spider, the one on the right from a bacterial infection.

Suspected bites occurring outside the native range of the brown recluse spider are particularly unlikely, given that surveys rarely yield recluses in non-native areas. Presumptive bites become even more unlikely if thorough inspection of the premises yields no sign of brown recluse spiders. If possible, anyone bitten by what is thought to be a brown recluse should try to collect the specimen and bring it to a qualified individual for identification. Even crushed or damaged specimens can usually be identified. Confirmation by an expert will help the physician decide on the appropriate course of treatment.

Controlling Infestations

Brown recluse spiders are difficult to eradicate, largely because of their secretive habits. Virtually any dark, undisturbed area can serve as harborage, and many such places occur within buildings. Because of this (and the potential health threat), treatment is best performed by professionals.

Where They Hide – Thorough inspection with a bright flashlight is needed to reveal the location and extent of infestation. Likely hiding places include crevices, corners, and wall-floor junctures, especially behind clutter and stored items. Reducing clutter affords fewer places for the spiders to hide and can enhance effectiveness of treatments. Brown recluse spiders may also live behind walls, and inhabit the voids within concrete block foundations. In infested garages, attics, basements and crawl spaces, the spiders, egg sacs, and distinctive shed skins are often found along joists, sills and rafters, as well as under rolled insulation. In living areas, they sometimes inhabit crevices behind and beneath beds and furniture, closets, clothing, shoes, and stored items. When sorting through boxes or materials, wear long sleeves and gloves to avoid being bitten. Brown recluse spiders also live above suspended ceilings, behind baseboards and woodwork, and within ducts and registers.


Fig. 8: Thorough inspections are needed to detect and treat hidden infestations.

Outdoors the spiders may be found in barns, sheds, woodpiles, and under anything laying on the ground. They also commonly reside behind shutters. Migration indoors can be reduced by moving firewood, building materials, and debris away from foundations. Sealing cracks and holes in a building’s exterior can further help to keep these, and other pests, outdoors. Some of the more common entry points for brown recluse spiders include gaps under doors, vents and utility penetrations, beneath the bottommost edge of siding, and where eaves and soffits meet the sides of buildings. Outdoor populations of brown recluse spiders are less common in the northern portions of its range.

Use of Glue Traps – An excellent way to survey for brown recluse is to install flat, sticky cards known as glue traps. Often used to capture mice and cockroaches, the traps can be purchased online or at grocery, hardware or farm supply stores. The best glue traps for capturing the spiders are flat, like thin pieces of sticky cardboard without a raised perimeter edge.


Fig. 9: Brown recluse spiders caught on a glue trap.
Several traps should be placed into corners and flush along walls.

The more glue traps used the better — dozens placed throughout a home will reveal areas where spiders are most abundant. Traps should be placed in corners and along baseboards and wall-floor junctures, especially behind furniture and clutter since spiders tend to travel in these areas. Besides being useful for detection, glue traps can capture and kill large numbers of spiders, especially the males, which are more likely to wander into places where people are accidentally bitten. Ongoing eradication efforts can be judged by the number of new spiders caught in traps. Glue traps should be installed before applying insecticides since some products will cause spiders to become active and wander into traps.

Use of Insecticides – Brown recluse spider elimination will often require use of insecticides. Some spiders will not be caught in glue traps, especially the adult females, which stay hidden more so than male spiders. Insecticides should be applied into cracks and other areas where spiders are likely to be hiding, attempting to contact directly as many as possible. Liquid, aerosol, and dust formulations may be employed.


Fig. 10: Insecticides are often needed to control infestations.

Dust insecticides are particularly effective for treating cracks along baseboards, sills, joists and rafters in basements, crawl spaces, and attics. Dusts also work well when treating under insulation, within voids of concrete block foundations, and behind light switch and outlet plates to contact spiders traveling along wires from attics. Effective dust insecticides include Cimexa®, Drione® and Tri-Die® (silica gel), Tempo® (cyfluthrin), and DeltaDust® (deltamethrin). Apply the dust as a fine deposit barely visible to the naked eye. Spiders and other pests tend to avoid powdery accumulations much as we would avoid walking through a snowdrift. The easiest way to apply such a small amount is with a ‘bellows’ hand duster sold in hardware stores or online.


Fig. 11: Dust formulations are easier to apply with a bellows duster.

Insecticides can also be sprayed into harborages and places where spiders tend to travel. Effective ingredients (e.g., cyfluthrin, bifenthrin, deltamethrin, lambda cyhalothrin) are often found in products used to control cockroaches, ants, and other crawling insects. The sprays can also be applied outdoors (behind shutters, the bottommost edge of siding, along foundations, etc. Total-release pesticide foggers known as ‘bug bombs’ are seldom effective against these spiders, and should only be considered when treating otherwise inaccessible areas.

Avoiding Bites

As control measures are being implemented, precautions can be taken to further reduce the chance of being bitten. Beds should be moved away from walls, and remove any bed skirts/dust ruffles to break contact with the floor. Shoes and clothing should also be kept off floors, or at least shaken out before wearing. Remove excess clutter and store seldom used items in plastic storage containers. There may be some comfort in knowing that bites are a rare occurrence, even in dwellings where brown recluses are abundant.

CAUTION: The use of some products may not be legal in your state or country. Please check with your local county agent or regulatory official before using any pesticide mentioned in this publication. ALWAYS READ AND FOLLOW LABEL DIRECTIONS FOR SAFE USE OF ANY PESTICIDE.

Please note that all photos in this publication are copyrighted material and may not be copied or downloaded without permission of the author.

Dr. Subba Reddy Palli
Department Chair & State Entomologist
S-225 Agricultural Science Center North
Lexington, KY 40546-0091
859.257.7450
[email protected]

Visit Us:

entomology.ca.uky.edu

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