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Most Dangerous Spiders in California

Since graduating university, Paul has worked as a bookseller, librarian, and educator. Born in the UK, he now lives in Florida.

If you want to find out more about the most venomous spiders found in California, read on...

If you want to find out more about the most venomous spiders found in California, read on...

What Are the Most Venomous Spiders in California?

There are two types of spiders that are capable of delivering venomous bites of note in California, qualifying them as being the most venomous and, in turn, the most dangerous. These spiders are widows and recluses. More specifically, the most dangerous spiders to look out for in California are:

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

Black Widow bites are somewhat common in California since this spider often lives in close proximity to humans. Although they are threatening to humans, death from a Black Widow bite is rare nowadays, thanks to the development of anti-venom. Pain and discomfort are most likely to be the worst results of a bite, and often there may be little to no effect.

Recluse bites tend to be rarer in California since the desert recluse, as implied by its name, resides in areas largely uninhabited by humans, and the Chilean recluse is only present in a few limited areas of Southern California. The most common species of recluse spider in the United States, the brown recluse, is not found in California.

How to Avoid Being Bitten by Widows and Recluses

Widows and recluses can be found both indoors and outdoors. You can lower the chances of being bitten by one of these spiders by:

  • Learning how to identify them
  • Understanding where you can expect to find them
  • Taking sensible precautions in areas where these spiders may reside, such as wearing gloves when reaching into spaces like high shelves, dark corners, sheds, and outhouses
  • Shaking out old clothes, towels, linens, etc. that have not been used for extended periods of time

Below is a full description of each spider type, including information on their habitats, behaviors, and bites.

Widow Spiders in California

As its name suggests, the Western Black Widow (Latrodectus hesperus) is found across western regions of the United States.

Is the Western Black Widow Venomous?

When it comes to bites, females are the ones to look out for, as it is they who carry potent, venom-containing neurotoxins.

What Do Western Black Widows Look Like?

Female Black Widows are jet black in color and have a distinctive red hourglass-shaped marking on their lower abdomen. In some cases, the hourglass can be yellow in color or even occasionally white. Their bodies are usually 12–16 mm in length, or 1/2 inch.

Male Black Widows look nothing like their female counterparts. They are brown to orange in color with light striping on their bodies and are generally harmless. The males are also smaller.

If you discover a web in your home, you may be able to discover whether or not it was the work of a Black Widow. These spiders do not follow any organized pattern when making webs. Unlike the tunnel webs or spiral webs that some other spiders make, Black Widow webs look messy and three-dimensional. They will commonly hang upside down near the center, and when they sense an insect (usually through vibration rather than by vision), they run over and bite it before covering it in their web.

What Happens if You Get Bitten by a Western Black Widow Spider?

Widows have a fearsome reputation when it comes to venomous bites, but the truth is you are unlikely to die when bitten unless you are particularly old and frail or a very young child. Still, treatment should always be sought straight away.

It should also be noted that Western Black Widows are generally timid and will almost always try to run away if they feel threatened. The only exception is if a female spider is guarding her eggs or if she is accidentally pinched or pressed against. This can occur when someone puts on a glove or shoe with a spider residing inside of it or if someone is reaching around in an area where a widow lurks, such as a high shelf or a dark recess.

Note that the bite itself may feel like a small pin prick or may not be noticed at all. The symptoms don't usually take effect until one to three hours after the bite.

Symptoms of a Western Black Widow Bite

  • Severe pain
  • Headache
  • Muscle and abdominal cramps
  • Nausea
  • Convulsions and tremors
  • Excessive sweating
  • Lesions in the bite area
  • Vomiting
  • Unconsciousness

At first, the venom only affects the area of the bite. Over time, the poison gradually travels through the body via the lymphatic system, and eventually makes it into the bloodstream. Symptoms normally persist for three to five days. It is extremely unlikely that a widow bite will be fatal if the victim receives immediate medical treatment.

Western Black Widow Spider Bite Treatment

You should never try to treat a Western Black Widow spider bite at home. If you have been bitten, consult your doctor immediately. Depending on your reaction to poisoning via a spider bite, your doctor may prescribe pain medication for relief. You may also be given medicine to lower your blood pressure, which may spike as a result of a bite from this type of spider.

If the bite is severe, you may need muscle relaxants or anti-venom. In some cases, you may need to be hospitalized.

There are some steps you can take before you go to the hospital to help reduce the damage. Make sure to:

  1. Wash the bite thoroughly with soap.
  2. Apply a wet or damp ice pack for 10 minutes at a time. Take 10-minute breaks in between.
  3. Elevate the location of the bite. (For example, if the bite is on your hand, raise your hand above your head.)
The Chilean recluse is generally considered to be one of the most venomous species of all the recluse spiders.  Although, as its name implies, it is native to South America, it is known to have established itself in the Los Angeles area.

The Chilean recluse is generally considered to be one of the most venomous species of all the recluse spiders. Although, as its name implies, it is native to South America, it is known to have established itself in the Los Angeles area.

Recluse Spiders in California

The Desert Recluse is the commonest type of recluse found in California. This species inhabits the eastern desert regions of the state. Bites from these spiders are rare, as the spiders are not usually found in areas that are highly populated by humans. There are also Chilean Recluses in the Los Angeles area of California. These are considered one of the more toxic species of the recluse family.

Are Brown Recluse Spiders in California?

Although brown recluses are common in many other parts of the United States, they do not inhabit the state of California. The only recluse spiders that can be found in California are the desert recluse and the Chilean Recluse.

What Are Recluses Like?

As their names suggest, recluse spiders are not aggressive by nature. They tend to bite only when pressed against human skin—for example, when an article of clothing is put on in which a recluse is living.

Recluse spiders are generally timid and seldom seen by humans. Bites usually occur when someone feels around in an area that they can’t see or when someone puts on an old item of clothing that the spider was hiding in.

Both the desert recluse and the Chilean recluse are varying shades of solid brown or tan.

What Happens if You Get Bitten by a Recluse Spider?

The effects of a recluse bite can vary enormously, from virtually no effect to death (in very rare instances).

Symptoms of a bite typically start between two to six hours after receiving a bite.

Symptoms of a Recluse Spider Bite

  • Blistering
  • Severe pain
  • Chills
  • Fever
  • Nausea
  • Necrosis at the site of the bite
  • Lesions

Unfortunately, there is no effective anti-venom for recluse bites, but by receiving medical care soon after being bitten, the bite can be treated. It should also be noted the recluse bites are often inconspicuous.

Recluse Spider Bite Treatment

As with Western Black Widow bites, go to the hospital right away if you are bitten by a recluse spider. Below are some steps you can take beforehand to treat a recluse spider bite.

  1. Wash the bite thoroughly with soap.
  2. Apply antibiotic cream.
  3. Keep the location of the bite raised to reduce swelling.
  4. Apply ice to the location of the bite.

What Is the World's Deadliest Spider?

The deadliest spider in the world is the Brazilian Wandering Spider. This is a large, brown spider resembling the North American Wolf Spider, but it is bigger and carries more neurologically active venom.

This type of spider resides in Central America and is an active hunter and traveler, hence its name. Like other spiders, it tends to hide in small, cozy spaces. It can also burrow into fruits and foods.

The Brazilian Wandering Spider, or BWS, as it is often referred to, will sometimes bite without administering its venom. However, if venom is administered, the receiver will feel immediate pain and a muscle shock. Multiple deaths have occurred within minutes of a bite. Some deaths have occurred even after anti-venom was administered. Children and seniors have a higher risk of death if bitten by this deadly spider.

As with most spiders, the female Brazilian Wandering Spider carries more venom and is more aggressive than the male.


This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2013 Paul Goodman


Tom from myspace on November 24, 2019:

Mark Halsey did you feel better after that extensive post? I bet you did. I will never cease to be perplexed by posts like yours, so self masturbatorial but with with such little to actually say. The wheels may be spinnin' but you ain't goin nowhere bud. So for everyone's sake please please please just say what you want or feel that you need to say in a straight to the point kinda way. Oh and maybe I'll see you around SD sometime and we can go spider hunting! Fingers crossed!!

reeeee on October 29, 2019:

in sb are alot of brown and black widows sometimes i think do they crossbreed

long stick on October 26, 2019:

take a long stick and poke at it if it runs up the stick and bites you its a brown

Bob Warnock on September 16, 2019:

No mention of the brown widow? It has established itself in southern California to the extent that it's under most pieces of yard furniture in Los Angeles and Riverside counties.

Scare D Cat on September 14, 2019:

Brown Recluses and Black Widows are all over Laguna Woods! True Fact!

Lucas on August 11, 2019:

If anyone actually cares, if you are talking about California you are at a 99.99% chance of mistaking the Desert Recluse for a Brown Recluse. Unless it is in an exhibit.

Brown Recluse are in the Southern and Midwest states. Think about humidity and dampness. The two species are very different in the habitats they thrive in. If I recall there are around 10 or so different species of recluse that are native to the continental USA.

Are there Recluse in CA, yep. are they brown, yep... Do we need to call them Desert Recluse? I'm not sure if the anti-venom treatment would be different... so medically, maybe?

Does anyone really care? Probably not.

John on July 24, 2019:

I have a good friend in SF bay area that was bitten by a brown recluse spider. At least that is what her doctor said after sending pics of the bite to CA Health dept . She was lucky and was treated but suffered sever symptoms, it's been a year and still has effects from the venom. after the bite, the state of CA closed off the area she was walking in and found several nests. It took months before they reopened the walking trails. They seem to like moist dark areas. Her dentist after learning that she was suffering from the venom effects

told her a friend he had died from a brown recluse bite he got on a golf course. He died within 6 weeks of the bite. Another women,in the same NoCal area was bitten on the leg and did not get treatment. After several weeks the leg was amputated and she still died shortly afterward. Don't think brown recluse spiders are not in CA. And don't take any spider bite for granted and try treating with over the counter meds. If you have a bite and it starts to develop an ulcer within 8 hrs of the bite, immediately seek emergency medical attention.

kent on June 24, 2019:

I had a brown recluse spider on me yesterday ( I am amazing so I killed it) IM SO AWSOME.

Kpal68 on June 16, 2019:

Hello, here in Meriposa, CA- I killed a brown recluse yesterday. Therefore they are here in and outside the deserts of California.

Bob Stone on May 27, 2019:

C E Bundy, you need to learn the difference between venomous and poisonous. Venom needs to be injected, while poison need to be ingested.

C E Bundy on May 20, 2019:

Don’t let anyone tell you that the Brown Recluse is not poisonous. Splitting hairs between the terms “venomous” or “poisonous” makes little difference when you end up in the hospital for a week while they give you anti-venom through an IV.

These are nasty creatures when it comes to their bite.

Tony Stark on January 08, 2019:

They are VENOMOUS not poisonous. Idk the actual differences between the two other than that you can drink venom and not die but i have heard of someone drinking a lot of rattlesnake venom and dying on A 1000 ways to die. (Not a very credible source noting that some of the people they say die actually get hospital treatment and live example: death by soy sauce) perhaps venom can only be biologically created and poison must be chemically created but again...theres no actual difference in that either.

K on November 17, 2018:

You know, if the Brazilian Wandering Spider wasn't so deadly, I'd almost want to keep it as a pet. It just looks so soft and I think it's kind of cute how it just wanders around exploring everything.

miro on September 19, 2018:

no there actually isn't

The girl that’s a on August 21, 2018:

Yes their is joe

Joey on August 17, 2018:

There is no such thing as a poisonous spider....

Mark Halsey on August 16, 2018:

I love reading Chatroom Forums, as there is always that one person who can’t resist but to get so fired-up about a particular topic, almost as if they are about to have a stroke or heart attack. And, for those who are interested, the Stroke, in addition to the Heart Attack, do exist in Southern California, contrary to popular opinion. Trust me, my dad is a doctor, who has told me a countless number of stories.

I live in San Diego, California (not San Diego, Texas), and have spent more time outside in many gardens, in addition to having either lived or spent a good amount of time, in countries around the world. That being said, I know a thing or two about bites, insect or otherwise.

Remember that Southern California is a desert climate. As a result, it is safe to assume that there are likely Brown Recluse spiders that have been able to adapt fairly well to the arid conditions, that is after they were stopped at the Arizona-California State-line, but happened to make it across the border without being caught. They are likely residing with your next door neighbor and you would never have suspected such a thing could be possible. Let’s be honest, with the vast territory, terrain, open land, parks, and basements left unfettered, I am personally very surprised there haven’t been more confirmed sitings of these rare arachnids, or identification of other new insect species, considering the changes in weather and climate we have seen within the past 20 or so years. These changes would undoubtedly create an advantageous environment for some creature. To say that the Brown Recluse cannot possibly be present in California is comparable to saying that there are no illegal immigrants living here either. You may not see them, but they are around us, blending in with their environment.

I do not profess to understand, nor belittle, significant scientific findings, however California is a very large state, with extreme changes in climate. As locating the Brown Recluse is likely not at the top of the to-do list for scientists, or the State of California, it is quite possible that they do reside here, but are extremely rare and perhaps more docile than their midwestern brethren, which could explain the lack of documented bite cases to support this, or any other claim.

That being said, due to all of the time I spend outdoors and in gardens, I literally get bitten by spiders on a weekly basis; I would say daily, but I would be lying. The point is, I work in dark crevices and spaces, without much regard for safety, as I use my bare hands, as opposed to wearing gloves, in order to be able to handle orchids, and other plants, with a finer touch. I normally do not notice having been bitten, nor by what insect, or more specifically, which taxonomy of spider. However, within several hours, I will notice a rash, scratch, or some other area, in which histamines have been released, at which point I take the necessary precautions and do my best to deal with the situation, never having to be taken to the hospital, even though I know that I have been bitten by some aggressive spider, with venom and neurotoxin. I have more scars than most groups combined, which should tell you for certain, that I have undoubtedly been bitten by some form of Recluse, Brown Widow, or Black Widow spiders in my lifetime.

The point I am attempting to make, is that even if it were a Brown Recluse spider, versus the Chilean Recluse, it really doesn’t make a difference, as there is no anti-venom for these bites, so what difference does it really make?! If we were talking snakes, I would understand the need to differentiate, so that one could receive the proper treatment for th venom. Since we aren’t discussing snakes, just know that being scared of spiders is pointless, their bark is truly worse than their bite, and as long as one takes the necessary steps to educate themselves, use common sense, and keep a good hygienic routine, you may start to look at spiders as just another insect, a Beautiful insect which should be revered.

A.Vanderpool on July 23, 2018:

How do you poison, kill spiders ? Any spider ?

Lucas on July 16, 2018:

There was a brown recluse in my bed a few days ago. I got up to turn on some music and before I sat down again I saw it and now I keep it as a pet.

Joe on June 06, 2018:

Dan, Black Widows were at on time bred because their webs were used as cross bars in rifle scopes. The webs were stretched and dyed black and used for the scopes. That was several decades ago, and I'm not sure if it's continued to be done.

Eddie Dunbar, Insect Sciences Museum of California on June 02, 2018:

Alternative facts!

Ec on April 11, 2018:

I have been attacked by these spiders in my room bitten... I feel horrible

Sam on March 31, 2018:

Ft Ord n ca 1975. Out on an overnight maneuver a Brown RECLUSE had crawled into my sleeping bag and that night I was bitten 3 separate places on my calf, woke up a few hours later in severe pain. Was taken to the army hospital and after they found it in my bag and it was confirmed. Still have the scars

dan on January 18, 2018:

I have both black widows and brown recluses around my houses in Manteca, California. I have personally seen them, killed hundreds of black widows each year, since the army thought it was good idea to breed them for some reason. I have killed a number of brown recluses already this year after cleaning my storage. So I promise you that they are here in california.

DJ on December 13, 2017:

oh...and, lighten up, Herbie! ;-) There absolutely have been brown recluse sightings in Southern and Northern CA. Google it.

DJ on December 13, 2017:

Most brown recluse spiders found in California have come by way of travel from other states, or countries. For instance, my ex husband was bit from inside his apartment in Woodland Hills, CA. Most people who live in the building travel most of year. Many from India. The spider was in someones suitcase and when they unpacked the spider crawled into his apartment.

DJ on December 13, 2017:

The desert recluse is the commonest type of recluse to be found in California. This species inhabits the eastern desert regions of the state. Bites from these spiders are rare as they are not usually found in high population areas, so encounters with humans are limited.

There are Chilean recluses in the Los Angeles area of California. These are considered one of the more toxic species of the recluse family.

(Although brown recluses are common in many other parts of the U.S., they don't live in California.)

Briar on November 18, 2017:

There have been cases all throughout Northern California, ESPECIALLY around Sacramento of brown recluse bites. Confirmed. By specialists! So many people in construction recognize the spider when asked if they’ve seen it. Who the hell is saying there are brown recluses all over the place except California? Do you have the spiders in your hand counting them off one by one? So far the evidence just seems outdated. A bite I had was consistent of a recluse bite(even if it wasn’t brown recluse). Unless you have a thorough, trustworthy, and updated research labs results, then I’m going to go with what current evidence suggests- there are brown recluses in California. Please share if you have a current, trustworthy, and thorough article. (lab results, where study was done, by who, for how long, what methods, etc) Thank you.

quahauq on November 16, 2017:

have image of desert recluse near Walker Pass California. 2 1/2 " across. request

shannon on October 09, 2017:

I live in San Jose California and there is an abundant population of brown recluse spiders I know many people who were hospitalized for their bites. They may have not originally been a native species I don't know but they are definitely here now.

herbie on October 06, 2017:

Anyone here who says that they, or that someone they know got bit by a brown recluse in California, doesn't know wtf they are talking about. THERE ARE NO POPULATIONS OF BROWN RECLUSE SPIDERS IN CALIFORNIA. I understand how convinced you are, and what the doctor said, or how the wound looked exactly or felt exactly like a recluse bite. Or how the symptoms were exactly like a recluse, etc. etc. etc. But the science and facts are that you were mistaken. Sorry.

Neversaynever74 on September 06, 2017:

I don't understand how you can say there are no Brown Recluse spiders in Northern California. They have the name Recluse for a reason. I live in Lodi Ca, hour away from Sacramento and my husband doesnt construction and was under a building and was bit by a Brown Recluse. Not just Recluse, it got in his boot . He was is in the worst pain I have ever seen him in. It was bright red with cellulitis was actually turning into liquid. They even had a specialist come in to confirm the bite. It was a Brown Recluse he called it ( Loxosceles reclusa, Sicariidae (formerly placed in a family "Loxoscelidae") This is what he wrote in chart and discharge papers. He had to go back everyday. So he wouldn't lose his leg. They said it is very rare . They get a couple of cases a year. Remember new species are discovered everyday all over the world. Your gonna say that you are 100% absolutely positive they don't reside in North. California. Yet where I live summers reach 110° We have tons of Black Widows. Now Brown Widow's. Brown Widows were only in Southern California, till about three years ago. They actually a threat to our Beautiful Black Widow. Black Widows are not aggressive. In fact they will actually run away and in most cases not even waste poison on a human. Only when threatened or pinched . Do more research. North America, the black widows commonly known as southern (Latrodectus mactans), western (Latrodectus hesperus), and northern (Latrodectus variolus) can be found in the United States, as well as parts of southern Canada – particularly in the Okanagan Valley of British Columbia, as can the "gray" or "brown widow ...

LaVerne on August 06, 2017:

Most recently, my church sister, Celine has been off work now for a few months after she went into cardiac arrest and mearly had her leg amputated from tbe bite of a recluse spider.

While concluding the burial ceremony for her Aunt; as mourners were leaving, Celine said she remembered watching the spider move about during the service but refocused her attention on the ceremony and she saw it again as she got up to leave and tripped and had fallen near THE AREA of the spider. She was helped up and remembers not seeing the spider again after her fall.

Well turns out...that spider got on her clothing and crawled under her pants and bit her leg a short time after her fall.

BECAUSE SHE WAS A BIG PERSON weighing nearly 350lbs she suffered many organ failure issues and stayed in hospital 2 months and now walks with a cain.

She lives in the Bay Area of CA. She was hospitilized at Highland Hospital.

I live also in Bay Area and am witness to seeing them and black widows in my suburban community in my back yard sheds and wood piles. I see some very ugly and scary spider in my home as well and so far not one of the two venomous ones. Celine recommends peppermint oil to clean walls, floors, and window (and cracks) along with keeping a tidy home throughout so they do not feel welcomed. I am scared since this has happened to Celine.

Devin on August 01, 2017:

I live in Northern CA and a friend of mine was bit by a brown recluse. It was in an old pair of gloves in the basement of his home, which he put on without shaking out. He lost the tip of his finger to necrosis...

So you can say there are no recluses in CA, but you would be wrong. There are always exceptions.

Logic on July 30, 2017:

As per UC Riverside's research, there are probably no significant, established populations of brown recluse in Cali. The vast majority, if not the totality, of supposed brown recluse bites occurring in the state are probably bites from another species of recluse (the Chilean recluse bite, for example, is particularly nasty and can cause severe necrosis and require hospitalization). Many commenters report the identification made by a physician as definitive, but a physician is not an entomologist! They probably properly identify a spider as a recluse, but their expertise is not in differentiating among all the species of recluse. Brown recluse is the one that everyone's heard of, so that's going to be the one most commonly named. Having said that, all these pronouncements that no one could have ever seen a brown recluse in Cali are equally absurd. The amount of human and vehicular travel into the state is astronomical. It's conceivable that several brown recluses periodically come across state lines--in someone's luggage, in cargo, ...etc. You can't dismiss an account with 100% certainty just because the probability that it's accurate is low. OK, you all can go back to drooling on yourselves now.

John Logothetis on July 28, 2017:

I got bitten by a brown recluse in L.A. We flew it to the hospital where it died shortly after it bit me. Very scary.

Jim on July 23, 2017:

Sorry Tom, UCR doesn't have the staff to look around all of California, what a joke. They didn't find any in their search, but they are not the pinnacle of researchers lol.

Tom on July 18, 2017:

There are no brown recluse spiders in CA, however there are recluse spiders. The Arizona Recluse, Baja Recluse, Chilean Recluse, Desert Recluse, Martha's Recluse, and Russell's Recluse can all be found in certain parts of California. Although they are not brown recluse they are very similar and do have the same type of venom.

RRuiz on July 17, 2017:

My husband and I were both bitten by recluse spiders in San Diego. It was documented and photographed by our physician. My husband got the worst of it but both of us suffered necrosis and staph. Our condo was infested with them in our closet and they were found in our clothes. We still have the scars. They do exist in CA.

Disbelieve on July 08, 2017:

Who died? Your dad or the doctor?

And i hope you are kidding

Canureed on July 08, 2017:

I think if you believe everything you read or hear on the internet... Then come buy some authentic Big Foot pictures from me.

I too have had friends claim they seen them or have been bitten by them. Creatures do migrate. More often then not things get misidentified and myths become facts. Anyone can write a story. Visit a University, speak to a person in that field. Call a pest control guy.

Spider Hunter on July 05, 2017:

One post someone tells the story of something personal the next post someone tells that person they are lying. I want to play. My father was a teacher who was bit by a brown recluse in La Habra California. He went to the docs and they told him there are no recluse spiders in CA. He died.

Aidan Sullivan on July 03, 2017:

No way there have only 10 BROWN recluse spiders caught and they were probably bought by shipments to California from the mid west there other reculse here but not brown reculse and no way two teachers were bit in California

edie on July 01, 2017:

I know 2 teachers who were bitten by brown recluse spiders. They both spent time in the hospital and said they they has abcesses on internal organs.

James Deathe on June 30, 2017:

There are no recluses in california.

Michele on June 29, 2017:

Sorry bust your bubble but I've been bitten by one almost died and almost lost my finger and I live in California so don't tell me

Erica on June 22, 2017:

Sorry....they DO exist in nor cal. My boss in Pollock Pines was bit in the calf, was flown to UCSF, had to have a lot of tissue and muscle removed, hospitalized quite awhile and most of his back calf was permanently gone. They had the spider and it WAS identified as a brown recluse. Granted this was a long time ago (early 90s) but they are seen at times up there.

brian lowdown on June 07, 2017:

they never hitch rides on trucks or all the daily cars,they check them at the arizona ,california border...also i think summers are a bit warmer with drought....vallejo ca and also desert areas have had brown recluse..i bet you can find on youtube...also call the ca pest control..the boa constrictor wasn't supposed to migrate to places they are now either.

Sara on June 02, 2017:

Two quick things- my MIL was bit years ago by a brown recluse in Petaluma, CA. She became very ill and was hospitalized at petaluma Valley Hospital. I believe that there are some in NorCal.

Secondly, I can on here to research in regards to who to talk to about spiders in our area. I came across one in my yard that I am pretty sure was a Brown Widow, and I have never seen one in our area. I heard that they had made their way to SoCal, but have never heard of them in NorCal. Any suggestions?

Not really in cali BUT.... on June 02, 2017:

My friend found one in California when doing a bug collecting project for college in orange county. There was a journal paper published on it and everything. That said the reason the paper was published was because they aren't really found in California so it was a big deal.

pat fox on April 12, 2017:

one of the nations best known spider doctors, also a well know author of all about spiders book, had a standing bet of $25.000 dollars, if some one in calif. filmed and authenticated a brown recluse spider and brought it in , no takers after 2 years, offer canceled, that was 2012

Tom on April 06, 2017:

The video:

Clean and repacking brown recluse spider bite;

Look up the mnemonic, NOT RECLUSE,

It's not,




NOT RECLUSE—A Mnemonic Device to Avoid False Diagnoses of Brown Recluse Spider Bites

Authors William V. Stoecker, Richard S. Vetter, Jonathan A. Dyer

Journal JAMA Dermatology

Tom on April 06, 2017:

No Brown Recluse in California ....!!!!

Look up:

UCR Spiders


University of California, Riverside, Myth of the Brown Recluse

Tony Tee, check it out and learn how to identify a Brown Recluse.

Scott, you took the spider to the medical center and they identified it as a brown recluse ....???? So the doctors are also entomologists ....????

Ryan, maybe you should be doing the research ....!!!

NorCal girl, you should contact UC Riverside and tell them about your evidence.... !!!

Ralph on April 01, 2017:

If you do some research, there are populations of recluse spiders in the southern deserts of California. But they are not the brown recluse. They could be the desert recluse or the Arizona recluse. They are related but are not the brown recluse.

Dan on March 22, 2017:

Def seen em in California

NorCal girl on March 16, 2017:

I have personally seen brown recluses and so has my dad. I know for a fact there are some here. Maybe not big populations but they are here. I am not miss identifying them either.

Scott on February 20, 2017:

I got bit in 2001 by a recluse while in bed in san diego the bite and spider were identified by Balboa naval medical center so i do believe there just might be recluses in socal

Mark on February 18, 2017:

I live in so cal. Once had a server pain in the leg. When I looked it was a large red rash with a small cut. A day later it swelled up and the small cut grew very large. 7 months later I still have a puffy scare. Does that sound like a recluse bite? I look at Google images and it was similar to a recluse, about twice the size of a black widow bite. What do you guys think?

exterminator on February 18, 2017:

Sorry but you are wrong. I am a licensed exterminator who is in the field every day. If you don't believe me, do a google search. The pest control industry, US government & ALL entomolgist/arachnologist agree that there isn't a brown recluse population in California.

If you are the cynical type (its a coverup!) consider this. Have you ever seen a pest control ad in California for brown recluses? Seems like a pretty big money maker considering the fear-mongering & hysteria... but legally we cannot treat for a target pest if that target pest doesn't exist in our area.

Think about it and do your own research, don't trust the testimony of that guy at a bar who swears his uncle/neighbor/ex-roommate knew a guy who knew a guy who saw one.

Ryan on January 21, 2017:

Esteban Vildoso actually they have migrated or been brought over to California, in recent years, we used to only worry about widows but now we have the recluse as well, maybe before talking down to someone who gives an informative article do a little research to see if the info you have is still viable.

Tony Tee!! on January 20, 2017:

I actually live in Petaluma ca, and work for the garbage company in the north bay and I come across brown recluse spiders, co workers run into them and Heard stories of them being in homes in Santa Rosa as well!!

Esteban Vildoso on January 02, 2017:

Why are you talking about brown recluse spider's they don't live in California.

Anna Marie Bowman from Florida on September 18, 2013:

I lived in Arizona for four years, and encountered a few Black Widow's during my time, and after seeing the pictures and video of the Brown Recluse, I am pretty sure I came across one of those, as well. Nasty little creatures! Very useful!