Some of the spiders in California are venomous, but by learning to identify some more common species, you can protect yourself against unintentionally disturbing one of them.
The rest of the spiders in California are not just harmless; they are beneficial to the state’s ecology.
Black widow spiders in California.
Black widow spiders in California are the easiest spider to identify. But, unfortunately, black widow spiders are also the most horrifying spider to identify up close and personal. The fear of the hourglass-shaped spider’s bite is world-renowned throughout the temperate regains of the entire world.
In many articles on black widow spiders in California, the author suggests that the reports of their venom and the inherent dangers of encountering black widow spiders are deemed “over-rated.”
That’s not true. Indeed, the black widow spider is nasty and potentially fatal to young and elderly humans. Therefore, any helpful article will recommend they be avoided, and those who live where black widow spiders reside can identify and avoid them.
The black widow spider in North America can also be red (Latrodectus bishopi ) or brown (Latrodectus geometricus). Despite their color, female black widows have dark-colored and easily identified reddish hourglass markings on the central underside. Only the female has a bite hazardous to humans.
Black widow spiders in California: Fascinating facts.
A study conducted in the 1950s found that 80% of black widow spider bites happened to men, most of whom were bit on the penis. Ouch! Why?
As reported in IFLScience.com, “Most of the black widow bites that were reported happened in outhouses.
“So black widow spiders enjoy dark, low-to-the-ground sort of places. They especially love to make their cobwebs between two objects,” she explained, adding that bugs and flies love the stink of outhouses and made their home in the privvy bowls.
“So putting your web there is excellent. So imagine this. It’s the 1950s. You’re a dude. You need to go number two. You make your way out to the outhouse. You sit down, and your junk hangs there.”
“And as it does, it hits the cobweb. And the usually non-aggressive black widow instinctually runs over and bites down on the new creature that has landed on its web.”
Since bathrooms began moving indoors, the problem (disproportionate targeting of men and penises) seems to have gone away. Their bites today are rarely fatal, with the majority resolving without treatment and others being treatable in hospitals. “
Need any more reasons to fear black widow spiders?
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Positively identifying brown recluse spiders in California.
Identifying brown recluse spiders in California begins by considering where you have found the spider in question.
Brown recluse spiders (Loxosceles reclusa) are commonly found in the Southern Central and Midwestern states. Sure, you could be looking at a traveler who has hitched a ride north, further east, or west. However, that spider is well outside its native territory. Indeed, it will never procreate enough to become an actual problem on the level of an infestation.
Traveling spiders (like the Hobo spider) sometimes enter and inhabit new regions. But the brown recluse spider won’t survive such migrations.
Brown recluse spiders: The eyes have it!
Adult brown recluse spiders in California are about the size of an American quarter (nearly an inch). Surprisingly, they are brown or tannish in color. Their abdomens and legs have no bands, mottling, stripes, or visible spines.
Don’t forget that they neither play violins or fiddles nor possess images of such musical instruments in markings or tattoos.
What sets the brown recluse spider in California apart from most other spiders you will encounter? First, they only have six eyes!
Retake a look at the close-up photo aboveYou’llll see that brown recluse spiders have a semi-circular eye arrangement (three sets of two), but most spiders have eight eyes.
Okay, I’ll admit that counting the number of tiny eyes on an inch-long spider is difficult. And no one has a magnifying glass at home, which is readily available anymore. So grab that iPhone, snap a photo, and zoom in on the spider’s face.
The slanting legs of the brown recluse spider in California.
Brown recluse spiders are rather plain with uniformly tan or brown abdomens, but their legs (which lack spines, as noted above) are covered in fine hairs. In addition, these legs are slanted (hence the scientific name Loxosceles, meaning slanted legs in Latin).
Brown recluse soldiers in California do not walk funny; instead, the rest with their legs slanted.
The Triangulate cobweb spider in California: Identification.
At first glance, this tiny Triangulate cobweb spider might be easily overlooked since it tends to build its cobwebs in dark corners of households and basements. Measuring only 1/8 – ¼ inch long, the cephalothorax is brownish-orange, while each of its yellow legs contains darker sections at their tips.
The abdomen has a finely pubescent texture with shades of brown and white, triangular spots along the mid-dorsal part, and irregular markings adorn the lateral area.
Triangulate cobweb spider: Habitat.
The Triangulate cobweb spider is found in abundance locally around houses in North America, spreading rapidly since its introduction. Although rare in South America, evidence of sightings has also been recorded there.
You’ll often find these brush-footed spiders (Theridiidae family) in urban environments, near human constructions, tucked away on walls’ dark corners, around windowsills, and beneath eaves. They weave irregular webs that they hang from as a trap for their victims, using the sharp bristles of their hind legs to ensnare them with sticky silk before finally biting down when the prey is stilled.
The Triangulate cobweb spider in California is a predator to be wary of, as it can often be found close to the brown recluse and common house spiders. Hiding out inside closets, crevices, and other nooks, this arachnid has been known to feast on ants, ticks, and pillbugs – not to mention its kind!
Texas dwellers should take extra care; reports indicate they may even prey upon fire ants nesting within utility equipment housings.
Brown widow spiders in California: Description.
The color of the brown widow spider (Latrodectus geometricus) is a mix of brown and tan spots and smears with contrasting black marks. It also has a black-and-white geometric pattern on the dorsal side of its abdomen, three diagonal stripes on each side, and bands on its legs. A prominent black mark is on the top of the diagonal stripes.
Like its cousin, the black widow spider, the brown widow spider in California has an hourglass on its abdomen. However, the color is muted orange and not the bright blood red found on the black widow.
The egg sacs of brown widow spiders.
For the layperson, telling a brown widow spider apart from younger black widow spiders is impossible. Fortunately, unlike most spider egg sacs best described as tiny, smooth cotton balls, the brown widow eggs sac looks like a sea mine.
The silk spikes covering the egg sac’s surface make positively identifying them as brown widow spiders easy for enough for anyone.
During her lifetime, a female brown widow spider can lay up to 150 eggs per sac and produce about 20 eggs per sac.
Brown widow spiders: Regions, habitats, and locations.
Brown widow spiders are currently found in Southern and Central California, South Carolina, Florida, Texas, and Georgia. Along with its native Africa distribution, they have been confirmed in Dominican Republic, Cyprus, the Americas, Poland, the Middle East, India, Pakistan, Thailand, Australia, Japan, China, and Hawaii.
Brown widow spiders in California prefer not to enter and build webs in homes, garages, or sheds, but they might. Instead, they like the protected spaces around your home. Empty buckets, underneath the seats of patio furniture, thick wooden vegetation, rockeries, mailboxes, the bottom of recessed garbage can handles, and eaves all make great places to build undisturbed webs.
Just noting the possible web locations raises an obvious point, when working or playing outdoors, you are much more likely to encounter and be bitten by a brown widow spider.
Cellar spiders in California: Identification.
Cellar spiders in California range from less than a 1/10th of an inch to 2/5ths in length. They have peanut-shaped bodies and oversized leg lengths, with some cellar spiders having long spans of nearly two inches.
The length of their legs is one key identifier; most cellar spiders have legs four times as big as their bodies. The other identifier is the body width being three times as wide as long.
They have eight eyes (grouped as two laterals of three and two smaller eyes whose borders touch each other. Cellar spiders have bodies that are colored gray, pale yellow, and brown and sometimes even appear as clear —with chevron marking.
Cellar spiders in California are found in every country and continent except Antarctica.
Cellar spider webs.
Cellar spiders make unsophisticated and unusual webs for a spider.
Like black widow spiders, they wait for their prey while hanging upside down. When prey is detected, cellar spiders vibrate their webs with their bodies, and this helps further entangle any insects caught in it.
When cellar spider bite, they inject a toxic venom (though it cannot harm a human) that is legendarily thought to be the most potent venom in the spider kingdom. This legend has yet to be scientifically proven.
Cellar spiders in California do not repair, clean, or remake their webs. Instead, they build additional layers on existing webs. This habit may save them time and energy, but in your home or barn, it quickly makes the web of a cellar spider conspicuous.
Red-Backed jumping spiders in California: Description
With a length of .4 inches, the adult red-backed jumping spider in California has a bright red abdomen and shining teal chelicerae. Most of its body is black in coloration, with females having a different black central stripe. This species has evolved to mimic mutillid wasps from the genus Dasymutilla (“velvet ants”), which are around the same size and have similar colors and painful stings.
Don’t mistake Phidippus johnsoni, a red-backed jumping spider commonly found throughout western North America, with the venomous Latrodectus hasselti, the red-backed spider. With its relatively large size compared to other jumping spiders, a red-backed jumping spider is one of the easiest species to recognize and identify.
Bold jumping spiders in California.
Bold Jumping spiders (Phidippus audax) are a member of the genus Phidippus. Notable features include their big eyes and iridescent chelicerae. All jumping spiders employ stereoscopic vision for hunting prey and communicating with potential partners during mating rituals.
Native to North America yet found in Hawaii, the Nicobar Islands, the Azores, and The Netherlands; these black arachnids are identifiable by the white triangle on their abdomen.
Bold Jumping Spiders in California are solitary hunters that rely on their impressive eyesight to track, capture and devour a range of arthropods, including caterpillars, dragonflies, and grasshoppers. It is common in agricultural areas and has also been studied to ascertain its influence on crop pest numbers. In contrast with most spiders constructing webs for prey-catching purposes, bold jumping actively hunts down their victims!
These spiders can be found in temperate climates in various terrestrial habitats, including grasslands, chaparrals, open woodlands, and agricultural fields. The bold Jumping spider in California is one of the most commonly occurring spider species within its range and is often found near humans. Bites from Phidippus audax are rare but may occur if they feel threatened or are mishandled. They are generally harmless, but victims must wash the area with water and mild soap if bitten.
Bold jumping spider: Description.
Bold jumping spiders in California are unmistakable creatures – females reach up to .6 inches in body length, whereas the males strand an oval abdomen, making them easy to spot!
The Bold jumping spider in California can easily be identified by its white triangular mark in the center of its back, accompanied by two more minor spots beneath it. Its upper abdomen is also marked with a distinct lateral white band that distinguishes this species. However, what stands out most about these creatures are their tremendous and powerful legs: males have distinctive fringes on their legs and pedipalp, while females boast a longer fourth pair of legs than those found on male specimens.
The chelicerae of adult males glisten emerald green and boast spectacular markings and tufts of fur over the eyes, whereas spiderlings’ chelicerae display orange hues that gradually lighten with age. Furthermore, Bold jumping spiders in California come in various sizes and colors depending on their habitat location.
Green Lynx Spiders in California: Description.
The female Green lynx spider is a sizable arachnid, ranging from .5 to .85 inches in length. Males are typically slimmer and shorter at an average of .5 inches. Their cephalothorax appears narrow around the eye region but broadens out significantly towards the back for increased stability.
The Green Lynx Spider in California has a vibrant transparent green body when alive that quickly fades away after being preserved in alcohol. It also features a red patch between the eyes and various sizes of red spots across its body, which vary from spider to spider. Additionally, it has a white flat-lying hair covering around the eye region while its legs are pale green or yellow with long black spines and flecked black spots along its femora for added color.
The vibrant, emerald-hued Green Lynx spider (Peucetia viridans) is the largest lynx spider in North America and can be seen atop shrubbery throughout the southern United States. The unmistakable arachnid stands out due to its impressive size and a beautiful hue.
The Green Lynx spider in California is a voracious predator of insects, but its bite presents little risk to humans. However, its potential use in pest control has captured the attention of agricultural scientists, who view this species as an invaluable tool for managing crop pests.
Common house spider in California: Description.
The common house spider in California comes in many muted shades, such as gray, tan, brown, or yellow. It also has darker skin patches or stripes running through its primary body color. The abdomen of the common house spider is higher than it is long and round in shape. Most common house spiders have darker-colored legs with bands or rings of color on them.
In the United States, females have yellow legs, and males have orange legs.
The larger female common house spider ranges from 0.12 to 0.18 inches. Due to their poor vision, these spiders usually do not flee from or even notice the approach of humans. Such poor vision is common among all web-weaving spiders.
There are over 200 species of common house spiders in the United States. The messy, billowy webs they construct easily identify them. These cobwebs function perfectly as entanglements for prey.
Common house spiders n California are part of the family Theridiidae (the widow family) and use their combed rear feet to pull silk from their spinnerets and toss it over entangled prey to immobilize them further.
Common house spider: Habitat.
One of the more interesting habits of the common house spider in California is the number of old, abandoned webs it leaves behind. The common web spider appears to select locations to create a web randomly, and then if they turn out to be unprofitable, quickly relocate their web to another site.
Inside your home, common house spiders build webs in the upper corners of bedrooms and living rooms, closets, sheds, garages, basements, crawl spaces, and even under your bed or behind your toilet.
Since most of the insects a common house spider in California preys on are drawn to natural light, they will build webs near windows.
Outside your home, common house spiders will create webs under eaves and within natural areas such as the entrance to a cave, hollowed logs, and barns and stables.
Huntsman spiders in California: Description.
The huntsman spider in California (Heteropoda venatoria) is a large (up to 1 inch long and 6 inches wide), flat, brown-colored, nearly hairless, invasive spider. Females are larger than males. Huntsman spiders are often mistaken for tarantulas.
The broad plate at the front of the huntsman spider’s eyes is cream to yellowish, and the cephalothorax’s hard upper ‘shell’ has a wide tan band on females and cream colored one on males.
Where do you find huntsman spiders in America?
The huntsman spider species that live in the United States can be found in the southern coastal states and parts of Florida, California, and Texas.
When they enter your home, they will tuck their flat bodies into the narrowest crevices and cracks. You’ll find them in closets, basements, sheds, garages, and even vehicles. Outside, they will conceal themselves in wood piles, construction materials, and openings in trees.
As colder weather approaches, huntsman spiders in California will attempt to find warmth in your home. Here they will prefer quieter locations where they are unlikely to be disturbed, such as inside curtains, closets, under cabinets, tables, and other furniture.
Spotted orb weaver in California.
The Spotted orb weaver (Neoscona crucifera) is a captivating arachnid in the Araneidae family, found from Maine to Florida on the East Coast and Minnesota in Midwest America, reaching down to Arizona and southern California.
This orb-weaver spider also has two common names: Hentz orb weaver or barn spider – although this latter name can sometimes be misused for another type of creature called Araneus cavaticus.
Spotted orb weaver: Description.
Typically active at night, female Spotted orb weaver spiders in California may switch to a daily schedule in the Fall. Females range between 0.35–0.75 inches long, while males are smaller in size.
The top of their abdomens is brown and hairy with alternating light and dark brown stripes on their legs; meanwhile, the underside displays two white spots against a black background.
The Spotted orb weaver in California boasts a wide array of colors and patterns but most typically displays rusty red or golden orange. Their webs are incredibly giant in circumference, often erected on artificial structures like buildings several feet above the ground level, particularly around outdoor lights.
Crab spiders in California.
The crab spider gets its name because it can hold its legs crabwise and move backward and sideways, not just forward. Mostar crab spiders are a member of the Thomisidae family; however, some belong to the Sicariidae (like the Brown recluse), Sparassidae (like the Huntsman’s spider), or Selenopidae (like Jumping spiders) families.
Researchers now believe crab spiders can change their color over time.
Crab spiders in California are also called Flower crab spiders, and many, like my favorite, the Goldenrod crab spider, can be found on flowers like roses and goldenrod. In the early Fall, the goldenrod plants around my home are teeming with goldenrod crab spiders, just waiting for the unwary butterfly or grasshopper to land nearby.
I won’t list them as actual predators later, so for now, I will point out that my chickens hunt them down like coyotes after rabbits.
Crab spider identification.
Crab spiders come in many colors, including pink, yellow, blue, black, white, and green. The easiest way to identify a crab spoiler is by noting the front four legs that are longer and thicker than the four rear legs.
The crab spider has eight eyes mounted on a lump on the front of their cephalothorax. They have two forward-mounted claws, flat bodies, and crabwise legs.
The crab spider can change color slightly with each molt, allowing it to camouflage itself against its current background. Some researchers believe crab spiders can even assume the colorations of their prey.
Crab spiders do not make a web, instead using a single start of silk to support themselves. Females wait for prey while sitting patiently on a plant or flower. Male crab spiders hunt while wandering around.
Special crab spider types.
In the Thomisidae family, there are 2100 species and around 175 genera.
The Goldenrod spider is of the genus Misumena, Misumena vatia in particular. They are one of the species of crab spiders known to change color from their normal or resting color to meet their predatory needs.
Bark crab spiders (Bassaniana) live camouflaged amongst the bark of trees while hunting prey.
Oxytate, which turns green to conceal itself in the grass or on a leaf.
Phrynarachne spiders that look like bird poop.
Black Lace-weaver spiders in California.
The fascinating thing about this spider?
After hatching, the Black lace-weaver in California is a matriphagous species, meaning their offspring devour her in cannibalism.
Black Lace-weaver: Identification.
This species of black lace-weaver is distinctive for its size, with females ranging from .4–.6 inches in body length and males slightly smaller at .3-.4 inches. Presenting a dark color palette including black, brown, dark red, and tan tones, the abdomen has light yellow markings that resemble an eerie skull mask or ghoulish pattern.
Habitat and distribution of the Black Lace-weaver.
In springtime, adult males of the black lace-weaver species are likely to be discovered indoors while searching for a mate. But, conversely, adult females can be found inside or outside year round! These creatures generally favor dark and humid places like underneath logs, in cellars, and in crevices tucked away beneath stones or worn-out walls.
The majestic Black lace-weaver spider is native to Europe and can be found throughout the continent. Yet, it has been specifically introduced into North America, New Zealand, and some Eastern European countries such as Turkey. Unfortunately, it cannot survive in Northern Europe due to its frigid temperatures.
Black lace-weaver webs.
The black lace weaver in California is renowned for creating an intricate cribellate web to capture prey and serve as a haven. This species receives its name from the woolly texture of the silk, which stems from fragile yet incredibly adhesive fibers. With this unique construction, it’s no surprise that many consider the web spun by these creatures simply exquisite.
The black lace weaver in California is particularly inclined to construct its webs on vertical surfaces, typically forming a befuddled jumble of threads that encase a circular shelter running into some crack. As soon as the web has been spun up freshly, it appears delicate and blueish in hue and is highly adhesive.
Generally speaking, this species weaves its most intricate webs at night, yet they will react promptly if any insect winds up caught in the net, irrespective of time.
Tropical Orb Weavers (Eriophora ravilla) are among the wide varieties of large orb weavers that can be found. Fortunately for humans, bites from this species are not known to result in any severe effects.
Tropical orb weavers in California: Description
Female Tropical orb weavers in California measure between 1/2 and one inch, boasting a spectrum of colors ranging from white to black. Typically these females are reddish-brown on their cephalothorax and legs with a grey or brown dorsum on the abdomen; additionally, they feature an unmistakable black triangular mark at the venter of their stomachs which is encapsulated by gray laterally while anteriorly and posteriorly it encircled by white.
The spider’s integument is further decorated with short light hairs known as setae that cover its carapace and legs. At times even displays bright yellow coloration within the front lateral corners of its abdomen.
Male Tropical orb weavers in California typically reach half an inch in length, with a dark grey abdomen much smaller than the females. The legs often have unique banding patterns, and the carapace displays a distinct deep longitudinal groove on its thorax. When males actively move around, their palpi become highly visible as they seem to flare outwards – making them stand out amongst other characteristics.
Woodlouse spiders in California.
The Woodlouse spider has a familiar and scientific name that tells you everything you need to know about it. The Woodlouse spider eat Woodlice. The scientific name (Dysdera crocata) suggests its color, saffron.
Despite this, the Woodlouse spider in California has many other names like the slater spider, pillbug hunter, sow bug hunter, and sow bug killer. All these names relate directly to the prey it fancies most. So, let’s begin with a picture of the prey, and we will get to the spider later.
Woodlouse spider: Description.
The Woodlouse spider in California has only six eyes arranged in an oval pattern. They have an orangish-dark brown cephalothorax and a yellowish-brown abdomen. The jaws of Woodlouse spiders are conspicuously large for a spider its size, slanted forward, and quite thick.
Female Woodlouse spiders can reach body lengths of .6 inches, with males usually under .5 inches.
All Woodlouse spiders have gleaming bodies.
The woodlouse spider is often mistaken for the brown recluse spider
Now, let’s take a peek at the Woodlouse spider.
Woodlouse spider: Habitat.
The first Woodlouse spiders in California came from the Mediterranean but were introduced to the United States, Asia, Chile, South Africa, and Australia. In the United States, they can be found from Georgia to Massachusetts and parts of western California.
Woodlouse spiders in California are typically found wherever woodlice are found under logs, plants, leaf litter, piles, bricks, and rocks. During the day, they will retreat to a silken hideaway woven into decayed wood or attached to the bottom of larger stones. They will take up residence in your home, as well.
Cross orb-weaver spider in California: Identification.
The Cross orb-weaver spider in California (aka, European garden spider, diadem spider, orangie, cross spider, and crowned orb weaver, is scientifically classified as Araneus diadematus. However, it goes by other names, such as the pumpkin spider, although this can be confused with another species: Araneus marmoreus.
This particular type of orb-weaving arachnid is native to Europe but has spread its webby wings over to North America, where it now resides too!
Cross orb-weaver spiders in California vary significantly in color, from the faintest yellow to a deep grey. Uniquely though, all of them have white mottling on their backs with four or more segments that form a cross shape. In terms of length, adult females reach up to 0.8 inches while males grow as long as 0.5 inches – and what’s more, they can sometimes consume the male after mating!
Banded garden spiders in California: Identification.
The banded garden spider in California (Agriope trifasciata) female may reach up to 1.0 inches in length, making them slightly smaller than the yellow garden spider. Its carapace is adorned with silvery hair. Its elongated oval abdomen tapers off at the posterior into a point without humps or notches like the yellow garden spider.
The background color on its abdomen is usually pale yellow/silver, along with multiple black lateral stripes for contrast. At the same time, their legs are also marked by lighter spots or bands among a paler hue of yellow.
Males of this species rarely exceed .2 inches in length, their abdomens a striking white. Immature banded garden spiders boast an almost entirely white dorsal surface to the abdomen. Furthermore, these arachnids’ egg sacs possess a similar texture and color as that of the yellow garden spider.
Further recommended reading about spiders.
Spider pages: Learn how to identify and avoid these spiders.