How do you tell if it’s a brown recluse spider?

Quick Answer

The brown recluse spider is well known for its appearance and poisonous bite. There are some key ways to identify them:

– Color: They are typically light to dark brown. The legs are a slightly lighter brown.

– Violin Shape: They have a dark violin/fiddle shape on the top of their body. This violin marking is the most distinguishing feature.

– Eyes: They have 6 equal sized eyes arranged in pairs.

– Size: Their body is about 0.5 inches long. Their leg span reaches up to 2 inches.

– Habitat: In the U.S. they are mainly found in the south and central states. They like dry, dark, abandoned places.

If you find a spider that matches this description in an area brown recluses inhabit, it’s best to exercise caution. Their venomous bite can cause pain, itching, nausea, and severe tissue damage. Seek medical help if bitten.

Identifying Physical Features

Brown recluse spiders have several distinctive physical features that help identify them:

Color and Markings

The most obvious physical trait is their coloration. As their name suggests, brown recluse spiders have a brown color overall. Their bodies are typically a light to medium brown. Their legs are a slightly lighter brown or tan.

The “violin” marking on their body is the clearest identifier. The violin shape is created by the body color being darker towards the eyes and midsection. This darker brown coloring appears violin or fiddle shaped when viewed from above. The neck of the violin points toward the spider’s rear.

Some varieties may have patterning, with darker markings on their legs and abdomens. But the violin shape on the main body section remains a constant.

Eyes

Brown recluse spiders have 6 equal sized eyes arranged in pairs, known as dyads. This sets them apart from other spiders that may have larger, prominent front facing eyes. The recluse’s eyes are small and similar in size and shape.

Size

The brown recluse is a relatively small spider. Their bodies are roughly 0.5 inches long. Fully grown, their leg span reaches around 2 inches. Some incorrect information sources state they are large spiders, but 0.5-2 inches is modestly sized.

For comparison, large spiders like tarantulas can have leg spans exceeding 5 inches. The recluse is nowhere near that big. Just a bit larger than a quarter coin. So be wary of any “brown recluse” larger than 2 inches – it’s likely a different type of spider.

Legs and Pedipalps

Brown recluse spiders have 8 eyes and 6 legs, consistent with spiders in general. Their legs are covered in short fine hairs. The leg joints may appear slightly thicker.

Between their legs are 2 pedipalps – small leg-like appendages near the mouth. These help the spider eat and move food. The pedipalps are about as long as the front legs and covered in tiny hairs.

Abdomen and Spinnerets

At the rear of the abdomen are 6 different sized spinnerets. These specialized appendages are used to produce silk. The two largest are the posterior lateral spinnerets. The four smaller ones are the posterior median spinnerets.

The abdomen itself is rounded at the rear and a bit narrower at the top. Some species may have visible fine hairs on parts of the abdomen as well.

Where They Live and Nest

Brown recluse spiders have a habitat range concentrated in America’s south and central states. They are also found in small sections of southern California, Nevada, and Oregon. Outside the U.S. they occur in Mexico and South America.

U.S. Habitat Range

In the United States, brown recluse populations are centered in the south and central Midwest regions. The states include:

– Kansas
– Oklahoma
– Texas
– Louisiana
– Arkansas
– Missouri
– Mississippi
– Alabama
– Parts of Georgia
– Tennessee
– Kentucky
– Ohio
– Indiana
– Illinois
– Iowa
– Nebraska
– Parts of South Dakota

There are isolated populations in southernmost California, Nevada, Utah, Colorado, and Oregon as well. But the main recluse zone is through America’s south central states.

Nesting Habits

Brown recluse spiders build irregular sheet webs in undisturbed, dry, abandoned locations. Some examples include:

– Old sheds or barns
– Attics
– Basements
– Closets
– Garages
– Wood and rock piles
– Hollow logs
– Crawl spaces
– Under furniture

They frequently nest near human homes since these buildings often provide warm, dry, secluded areas. But the spiders aren’t limited to human dwellings. Any sheltered spot works well.

Their webs don’t have a classic spider web shape. Instead they spin messy, asymmetrical sheets with strands extending in all directions to nearby surfaces. These webbed shelters provide protection while they wait to ambush prey.

Venom and Bite Dangers

The brown recluse has a feared reputation stemming from its venomous bite. Though the spiders aren’t aggressive, they will bite in self-defense if threatened.

Venom Composition

The venom is composed of toxic enzymes and proteins, including:

– Sphingomyelinase D – causes cell damage
– Cytolytic peptides – punches holes in cell membranes
– Small molecules – disrupt cellular processes

When injected into skin tissue, the venom kills skin cells and destroys cell membranes. The damaged area then becomes inflamed and necrotic.

Bite Symptoms

A brown recluse bite may go unfelt initially. Within 2-8 hours, bite symptoms emerge:

– Mild burning at the bite site
– Intense itching
– Sharp stinging pain
– Blister formation
– Opening of the bite wound as the blister pops
– Ulceration – breakdown of tissue leaving an open crater-like wound

Systemic symptoms like fever, chills, nausea, vomiting, and tiredness may follow a day or two after the bite. Severe reactions cause systemic organ damage in rare cases, especially in children.

Bite Treatment

See a doctor quickly if bitten by a brown recluse. Early medical care improves outcomes.

Possible treatments include:

– Cleaning and bandaging the wound
– Antibiotics for infection
– Steroids to reduce inflammation
– Surgery to remove damaged tissue
– Antivenom in severe cases
– Hospitalization for organ damage monitoring

Even with treatment, healing takes several weeks or months. Scarring often results. Prompt medical attention is vital.

How to Control Brown Recluse Populations

If brown recluses have become a problem in your home, there are some population control methods you can try:

Physical Removal

Manually eliminating spiders and egg sacs is the most direct option. Their large leg span makes them easier to spot and remove. Take precautions like wearing thick gloves and using an object for removal without direct hand contact. Placing sticky traps in garages, attics, basements, and closets is another manual removal technique. Check and empty the traps regularly to dispose of captured spiders.

Habitat Modification

Brown recluses thrive in dry, abandoned spaces with lots of debris and clutter. Keeping your home’s storage areas, basements, attics, etc clear of unnecessary clutter helps reduce nesting sites. Regular vacuuming and sweeping also removes webs. Fixing moisture problems like leaks helps make the environment less hospitable. Sealing cracks and crevices removes entry points.

Pesticides

Insecticide sprays and dusts containing chemicals like cypermethrin, deltamethrin, or permethrin can be applied to known spider hotspots. Consult a professional exterminator for whole-home treatment. The chemicals kill spiders and elders on contact. Apply pesticides in corners, under furniture, in storage spaces, etc. Follow all label instructions carefully.

Traps

Glue traps and boards are a chemical-free control option. The spiders get stuck on the adhesive surface when investigating the board. Place traps along walls, in cabinets, or under furniture. Check them regularly to dispose of trapped spiders.

Natural Predators

Promoting brown recluse predators like house centipedes, spiders of certain types, and pseudoscorpions can reduce populations naturally. Avoid killing these beneficial predatory species if possible.

Frequently Asked Questions

Here are answers to some common questions about identifying and dealing with brown recluse spiders:

What color are brown recluses?

Brown recluse spiders are light to medium brown in color, with slightly lighter brown legs. Some variations may be darker brown. The violin marking on the body has an even darker brown shape.

Do brown recluses live in groups?

No, brown recluses are solitary spiders. They don’t spin organized webs or live in communal groups. Each spider inhabits its own small messy web built in a secluded location.

What does a brown recluse bite feel like?

Initially the bite may go unnoticed. Within 2-8 hours, a stinging or intense itching sensation develops. Pain, blistering, ulceration, and tissue death occur in the days following as the venom damages cells. Systemic symptoms like fever may also arise.

What does a brown recluse bite look like?

The bite forms a small blister at first, surrounded by a pale ring. As the blister ruptures, an open ulcerated wound is left. This crater-like lesion has a dry blackish center with ragged edges. The venom kills tissue, leaving an expanding dead area.

How big do brown recluses get?

Brown recluse bodies are roughly 1/2 inch long. Their leg span reaches about 2 inches when fully grown. Some inaccurate information mistakenly states they are large spiders, but they are moderately sized.

Where do brown recluses live in the U.S.?

In the southern, southcentral, and central Midwestern states. The main concentration is in Oklahoma, Texas, Kansas, Arkansas, Missouri, Louisiana, Mississippi, Alabama, Tennessee, Kentucky, and parts of adjacent states. Small isolated populations live in the far southern California, Nevada, Utah region as well.

Do brown recluses live in groups?

No, brown recluses are solitary spiders. They don’t spin organized webs or live in communal groups. Each spider inhabits its own small messy web built in a secluded location.

How do you get rid of brown recluses?

Seal cracks, remove clutter, vacuum regularly, manually eliminate spiders, apply pesticide sprays or dusts, use sticky traps, and promote natural predators like centipedes. Population control takes diligent multi-method efforts.

Conclusion

In summary, identifying brown recluse spiders involves recognizing key physical traits like the violin marking, eye arrangement, small body size, and leg features. Being aware of their habitat range in America’s south and central states is also useful. Their venomous bite can be dangerous, so seek prompt medical treatment if bitten. Reducing clutter and employing various population control methods helps limit brown recluses in your home. Let this guide help you identify, avoid, and control brown recluse spiders.

Trait	Description
Color	Light to dark brown body. Legs slightly lighter brown.
Markings	Dark violin/fiddle shape on top of body.
Eyes	6 equal sized eyes in 3 pairs.
Size	0.5 inch body length. 2 inch leg span.
Habitat	Southcentral and central U.S. Dry, abandoned places.
Webs	Irregular messy sheets of silk threads.

Bite Stage	Symptoms
Initial bite	Puncture marks. Mild burning.
Few hours later	Severe pain. Blister forms.
1-2 days later	Blister ruptures. Wound ulcers.
Days after	Tissue damage spreads. Necrosis.
Potentially follows	Fever. Organ damage.

Control Method	Description
Physical removal	Manually eliminate spiders. Use sticky traps.
Habitat modification	Reduce clutter and seal cracks.
Pesticides	Apply chemical sprays or dusts.
Traps	Use boards or glue traps.
Natural predators	Promote centipedes, spiders, etc.