Are Brown Recluses in California?

In a nationwide study of Brown Recluse spiders, people were asked to send photos of spiders they thought were brown recluses. Brown recluses are highly venomous and can cause a sore that lasts for weeks and leaves a deep scar, so somewhat concerning.

There were 600 different entries from California, claiming they had a photo or sample of a venomous brown recluse. Were all of those just “brown spiders” or were some of them brown recluses? Are Brown Recluses in California?

Let’s find out.

What is a Brown Recluse Spider?

Brown recluse spiders do live in the United States. Their bodies are about a half-inch with longer legs and a body larger than their head. The body is lighter in color than the head and legs which are a darker brown.

They are sometimes called “violin spiders” because of the violin-shaped markings on their head. It is not that common to come across a brown recluse because, as their name suggests, they are recluses and live in hidden spaces like under rocks, logs, or leaf piles and inside in cellars, basements, and attics. Brown recluse spiders are venomous and have a painful bite that starts to kill skin and nerve cells.

According to Medscape their venom “can cause significant cutaneous injury with tissue loss and necrosis.” It is cytotoxic and hemolytic, attacking skin cells and can leave a large scar, even after medical treatment. 

Are Brown Recluses in California?

No. There are no breeding populations of Brown Recluse spiders in California. There are spiders that look like Brown Recluses and there are other Recluse spiders like the Desert recluse that do live in California, but Brown recluse spiders do not live in California.

What States have Brown Recluse Spiders?

• Alabama
• Arkansas
• Georgia
• Illinois
• Indiana
• Iowa
• Kansas
• Kentucky
• Louisiana
• Mississippi
• Missouri
• Nebraska
• Ohio
• Oklahoma
• Tennessee
• Texas

Are There Other “Recluse” Spiders in California?

Yes. There are 4 species of recluse spiders that live in California including the Desert recluse and the Chilean recluse. Both of these species are venomous as well and look similar to the Brown recluse. So even though there are no Brown Recluse spiders in California, their cousins do live there and can be harmful to humans.

Are There any Other Venomous Spiders in California?

Yes. The three most venomous spiders in California are:

• Western Black Widow (Latrodectus hesperus)
• Desert Recluse (Loxosceles deserta)
• Chilean Recluse (Loxosceles laeta)

Are Black Widows and Recluses Just as Venomous?

Black widows and recluse spiders have different kinds of venom. They have venom that attacks the nervous system. They are the deadliest spider in the United States, but not the deadliest spider in the world. If you are bitten by a Black Widow you will feel the effects right away.

You may feel severe pain at the bite site and then muscles will tighten, you may feel nauseous or vomit, and experience abdominal pain or cramping and excessive sweating. If you think you have been bitten by a venomous spider you should seek immediate medical attention, especially for children and seniors.

Are Black Widows in California?

Yes. Black Widow spiders do live in California. The Western black widow spider is located throughout California but prefers to live outside, not inside homes. Although the spiders are relatively common, bites from Black widows are pretty rare. According to the California Poison Control System (CPCS) there were 2,400 calls related to spider bites in 2017, as an example. Again if you think you have been bitten by a spider, check with your local medical facility for evaluation.

Effects from the venom may take hours to kick in so be aware over a period of time about the symptoms.

What Can You do to Prevent Getting Bitten by a Venomous Spider in California?

There are a few habits you can use to help prevent getting bitten by a spider. For recluse spiders, remember that they prefer “recluse” areas. So anytime you are moving a box, putting on shoes, or cleaning a closet that hasn’t been used for a while, these are places where spiders may have made their home.

What do You do if You Have Been Bitten by a Venomous Spider?

If you have been bitten by a venomous spider you should seek immediate medical attention. An antivenom is available at medical facilities in the U.S. and can help ease the discomfort and shorten the time of recovery. Being able to describe the spider that bit you, or bringing it in can help medical professionals know what next steps to take. As we have discovered, Brown recluse spiders do not live in California so you can rule those out.

How do You Know if it is a Brown Recluse spider?

There are 5 characteristics that all Brown Recluse spiders have. The first is all about their eyes. Most spiders have 8 eyes, with 2 rows of 4 eyes lined up. Brown recluses have six eyes, with two eyes in the middle of their head and two eyes on the left and right side.

They have a body that is all the same color, usually a light tan. Brown recluses have no spines on their legs. If you look at some spiders, like the spiny orb-weaver, they have hair-like spikes coming off their legs, but Brown recluses do not have these. Their legs are all the same color vs. having different segments of different colors and they do not get more than 3/8 inch long (their bodies).

Where is the Closest Brown Recluse to California?

The farthest west that Brown recluse has made it so far is Texas, Oklahoma, and Kansas. So if they gradually made their way across the country west, they would need to go through New Mexico, Colorado, Arizona, Utah, and Nevada before invading California.

But Brown recluse spiders do not generally expand their range. They reproduce and stay in the same general area as the spiders before them so it is not likely that Brown Recluse would end up living in California.

What Venomous Spiders Are Found in California?

In California, the following venomous spiders are found:

1. Black widow spider: This spider has a distinctive hourglass-shaped marking on its back and is known for its potent venom. Black widows are usually found in dark, undisturbed areas and are not aggressive, but will bite if they feel threatened.
2. Brown widow spider: This spider is similar to the black widow but is less venomous. It has a brownish or grayish coloration and an hourglass-shaped marking on its abdomen. Brown widows are often found in urban areas and are known for their tendency to spin webs in protected spaces such as garages and sheds.
3. Hobo spider: This spider is native to Europe but has been introduced to the Pacific Northwest and is now found in parts of California. The hobo spider is not considered to be highly venomous, but its bite can cause pain and swelling.
4. Yellow sac spider: This spider is yellowish-green in color and is often found in homes and gardens. Yellow sac spiders are not considered to be highly venomous, but their bites can be painful and may cause local swelling and redness.

It’s important to note that while these spiders can be venomous, bites from these species are rarely fatal to humans. If you are bitten by a spider and experience severe symptoms, seek medical attention immediately.

The photo featured at the top of this post is © Pong Wira/Shutterstock.com