Most Dangerous Spiders in California
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 poisonous 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 the California, since this spider often lives in close proximity to humans. Although threatening to humans, death from a Black Widow bite is rare nowadays, thanks to the development of anti-venom. Pain and discomfort is most likely to be the worst result 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, cannot be 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 to you can expect to find them
- Taking sensible precautions in areas where these spiders may reside, such as wearing gloves when reach 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 hour glass 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 straightaway.
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
- Muscle and abdominal cramps
- Convulsions and tremors
- Excessive sweating
- Lesions in the bite area
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 a 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:
- Wash the bite thoroughly with soap.
- Apply a wet or damp ice pack for 10 minutes at a time. Take 10 minute breaks in between.
- Elevate the location of the bite. (For example, if the bite is on your hand, raise your hand above your head.)
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 theyspiders 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 suggests, 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
- Severe pain
- Necrosis at the site of the bite
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.
- Wash the bite thoroughly with soap.
- Apply antibiotic cream.
- Keep the location of the bite raised to reduce swelling.
- 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.
Handling a Male Brazilian Wandering Spider (Video)
- "Black Widow Spiders". Orkin Pest Control. Retrieved 19 June 2017.
- Burkhard Bilger (March 5, 2007). "Spider Woman: Hunting venomous species in the basements of Los Angeles". The New Yorker.
- Vetter, Rick. "Myth of the Brown Recluse Fact, Fear, and Loathing". UCR Spiders Site.
- "Western Black Widow (Latrodectus hesperus)". The Royal Alberta Museum. The Royal Alberta Museum.
© 2013 Paul Goodman