Spider Survey

Grass Spiders or Funnel Web Spiders spin sheet webs with a funnel shaped retreat at the edge where they rest. When an insect walks across the web, they rush out to capture it and drag it back into the retreat.  They are medium to large spiders with a characteristic pattern.  The carapace is light with dark longitudinal bands.  The abdomen is dark gray, often with a broad orange median band.  The long spinnerets are easily seen.

When mature, the males go in search of females.  Mating takes place within the retreat or on the sheet web.  The male may remain with the female until he dies.  The egg sac is placed in the retreat where the female guards it until the young hatch and disperse.

Genus: Hololena
Hololena curta – This native spider is one of the most common spiders in the area and has been found in a wide variety of habitats.  Its sheet webs can be found in large numbers in bushes and hedges, often very close to each other.  They also spin their webs in the corners of houses and garages and in the corners of windows.

Genus: Agelenopsis
Agelenopsis aperta – This large spider prefers open dry areas where it spins its sheet web in grass or at the base of bushes. The retreat usually extends down into grass or into a crevice. This spider has been collected in local mountains and adjacent areas.

Genus: Tegenaria
Spiders in this genus spin their webs in houses and under bark and rocks. The abdomen is gray with a pair of light streaks.
Tegenaria domestica – This is an introduced species which is found worldwide. It is usually collected in houses and has been found throughout the area.
Tegenaria pagana – Also an introduced species, one spider has been collected in the San Gabriel River wash.

Genus: Calilena
Spiders in this genus spin their webs under rocks and boards and in leaf litter.  Three species have been collected in the area.
Calilena angelena – This spider has been collected in Zuma Canyon,
Calilena californica – This spider has been collected in local mountains.
Calilena stylophora – This spider has been collected along the San Gabriel River wash.

Spiders in this family range from large to very small.  They are usually brownish gray in color, sometimes with chevrons on the abdomen and are found in leaf litter and under logs and rocks.  The survey has collected three species in the genus Amaurobius.

Amaurobius dorothea – These medium sized spiders have a dark orange carapace and gray abdomen with a chevron pattern.
Amaurobius latescens – These medium sized spiders have a dark orange carapace and gray abdomen with a chevron pattern.
Amaurobius agastus – One specimen has been collected in the Santa Monica Mountains.

One species, Metaltella simoni, has been introduced from South America and has recently spread throughout the Los Angeles area.  It spins a tangled web under leaf litter, bark and rocks.  It has been found in gardens and houses.

Gertschanapis shantzi – These tiny spiders have been collected in leaf litter in the Santa Monica Mountains.

Spiders in this family are wandering hunters found in leaf litter and under bark and rocks. They are pale yellow or tan, sometimes with dark markings. They rest in silken retreats under leaves and stones. Egg sacs are soft white and round, and may contain from 50 to 150 eggs.

Genus: Anyphaena

Anyphaena pacifica – These spiders are pale orange with a reddish abdomen.  Rapid hunters, they are found under rocks and occasionally wandering in houses.  In our area, they are more commonly collected in houses.

Anyphaena californica – This spider has a pale abdomen with dark transverse markings.  It is more likely to be found outside in gardens, and has been collected from compost piles.

Genus: Hibana incursa – Similar in appearance to the others, this spider has dark chelicerae.

Most noticeable in the late summer and autumn in their large orb webs, most of these spiders are native to the Los Angeles area.

Members of this family vary greatly in size. Most have an annual life cycle with one generation per year. Spiders mature and mate in early summer and fall. Males die shortly after mating; females die after making an egg sac. The spiderlings hatch and remain in the egg sac until spring, typically undergoing their first molt before leaving the egg sac.

The orb shaped webs are usually vertical; most spiders have a retreat in which they remain during the day. The spider usually sits in the middle of the web during the night. Some members of the family take the web down at dawn and rebuild it at dusk. Others just repair damage caused by flying insects. Often the spiders will consume the silk and recycle it.  Males are less commonly seen than females.  They are smaller and once they have undergone their final molt and are mature they no longer spin webs. The remainder of their lives is spent searching for females to mate.
 
GENUS: Araneus
This  genus includes many of the larger orb weavers found in North America, as well as many smaller species. Most are native. They are nocturnal, resting in a silken retreat during the day and hanging in the center of the web during the night. Most have a pair of humps at the anterior margin of the abdomen. The loose fluffy egg sac is left in a sheltered spot.

Araneus gemma – This spider is one of the most commonly seen in gardens in the fall sitting at the center of the web at night.  Large (females are 9-19mm.), the abdomen is brownish orange with a median longitudinal white streak.  The underside of the abdomen has a black band bracketed by white.

Araneus gemmoides – This spider is very similar to Araneus gemma. The ranges of the two species overlap along the Pacific Coast and it is thought that they are interbreeding.  Some spiders in our area appear to be hybrids.

Araneus andrewsi – Also large, this spider is dark with a dorsal folium.  They are usually found in trees.

Araneus nordmanni – This large spider varies from light to dark with two white spots on the underside of the abdomen, and is usually found in forested areas.

Smaller Araneus species: Most of these smaller spiders mature earlier than the larger ones, in spring rather than late summer, when their prey is still small enough for them to catch. They have been collected in gardens and local mountains.

Araneus bispinosus

Araneus montereyensis

Araneus monica

Araneus pegnia

GENUS: Argiope

Very large and colorful, spiders in this genus can be seen hanging upside down in the center of their large orb webs, typically with legs stretched out in an X. The webs often have a stabilimentum, a zigzag band of silk, down the middle of the web. The purpose of the stabilimentum is unknown, although scientists have suggested several hypotheses:  camouflage and protection for the spider, a diversion for birds, an attraction for insects.  The males are minute in comparison to the very large females.  They can sometimes be found at the edges of the web.  Their small size may be protection from becoming dinner for their mate since they are too small for the female to bother eating.

Three species have been collected in the LA area in the survey although they are less common than other large orb weavers.

Argiope aurantia  – The Black and Yellow Argiope is found in gardens, hanging upside down at the center of its large orb web. The egg sac is a brown papery sphere and may contain 400-1000 eggs.  The eggs and spiderlings spend the winter inside the egg sac before hatching and dispersing.

Argiope trifasciata – The Banded Argiope has a white, yellow and black striped abdomen and is found in gardens and open areas.  It prefers drier areas than the Black and Yellow Argiope. The web is usually close to the ground in bushes and grasses. The egg sac is brown and papery, flat on top and rounded underneath, and may contain 100 eggs.

Argiope argentata – The abdomen of the Silver Garden Spider has several lobes along the sides.

GENUS: Cyclosa

Members of this genus are found worldwide; two are found in our area. They are found hanging in the web during the day. The web has a vertical line of debris down the middle which gives the spider its common name, the trash line spider. When disturbed in the web, the spider will rapidly shake the web then escape by dropping on a line of silk.  The abdomen of the females extends into characteristic posterior humps.

Cyclosa conica – The abdomen of the female of this species has a distinctive posterior hump. 

Cyclosa turbinata – The females of this species have a pair of humps on the anterior margin of the abdomen in addition to the posterior hump. 

GENUS: Eriophora edax – This large spider has a triangular abdomen with a black trapezoidal mark surrounded by white on the ventral abdomen.

GENUS: Eustala – Three species have been collected in our area.

Eustala californiensis

Eustala conchlea

Eustala rosae

GENUS: Larinia – One species Larinia directa, has been collected.  It has an elongated and stripe abdomen.

GENUS: Larinioides

Larinioidae patagiatus

Larinioides sclopetarius

GENUS: Mastophora

One species in this genus is found in the L.A. area. The Bolas spider, Mastophora cornigera, is also called the bird turd spider because it resembles a bird dropping as it sits at rest.  In the Orb Weaver family, it is the exception; it does not spin a web.  The spider emits a pheromone that mimics that of a female moth.  When the male moths come looking for the female, the spider catches the moth by swinging a line of silk with a glob of sticky silk at the end.

Although not common, it is widespread in the area.
 
GENUS: Metazygia – Two introduced species have recently been collected in the Long Beach area.

Metazygia wittfeldae

Metazygia zilloides

GENUS: Metepeira – These small spiders prefer the mountains around the L.A. area and are commonly found on native buckwheat and sage.  The orb web has an irregular retreat.  All species have an oval abdomen with a folium and a longitudinal white stripe on the underside of the abdomen; some also have a white stripe on the sternum.  The egg sacs are brown flattened ovals, hanging in a line below the retreat.

Species collected in the local mountains include:

Metepeira crassipes

Metepeira foxi

Metepeira grandiosa grandiosa

Metepeira ventura
 

GENUS: Neoscona

These large spiders are one of the most common and abundant of the orb weavers, frequently seen in their vertical webs in late summer. They spend the day in a retreat at the edge of the web and hang in the web at night. Like the Araneus species, they usually live for one year, spinning a flattened egg sac covered with loose silk in foliage in the fall before dying.  The egg sac may contain as many as 300 eggs.

Neoscona crucifera – This is the most commonly collected orb weaver in the L.A. area.  It is found around houses, in gardens, and in open woods.  The spider sits in the center of its web at night.  It has an oval abdomen with an indistinct darkish pattern.

Neoscona arabesca – These spiders have an oval abdomen with paired black dorsal lines, and are found in shrubs and meadows.  They prefer sunny moist conditions.
 
Neoscona oaxacensis – Commonly found near houses in shrubs and tall grass, these spiders have a black and white pattern on the abdomen.  They can be found throughout the L.A. Basin.

GENUS: One species, Zygiella x-notata , has been collected in the area. Originally from Europe, it is an introduced species. The small spider has an oval abdomen with a black and white folium.  The orb web is incomplete; the spider leaves an open sector or wedge.

These small to medium sized spiders are usually pale brown to yellow. They are nocturnal wandering hunters who spend the day in a silk-lined retreat under a rock or in a rolled-up leaf.

One species, Clubiona pomoa, has been collected in the Agoura area.

Most of the spiders in this genus are ant mimics, often found running rapidly over leaf litter. They are small and often brightly colored.  Three species have been collected in the survey.

Castianeira alfa

Castianeira Athena

Castianeira luctifera

Genus: Falconina gracilis, a species native to south America, has been collected in the south eastern part of Los Angeles County.  It is found in damp areas, under rocks, logs and trash cans.  The pattern on the abdomen is characteristic of the species.

Spiders in this family are large mygalomorphs who live in silk lined burrows with a trapdoor. The spider waits at the open trapdoor for an insect to pass by, and then rushes out to grab it.  The males are more likely to be seen after winter rains when they leave their burrows to go in search of females.  The females may spend their entire lives within their burrows.

Bothriocyrtum californicum is the native trapdoor spider in our area.  It has been collected in gardens adjacent to local mountains following winter rains.  This spider is declining in number due to habitat loss and increased urbanization.
 

The Gray House Spider, Badumna longiqua, has been introduced from Australia. It is a large dark brown spider covered with lighter hair. It is found around buildings along the coast.  The spider spins a characteristic messy web with a retreat at the side where it rests.

Spiders in this family are mostly small with a round to oval abdomen. Some are found in leaf litter. Others spin small irregular webs in the branch tips of trees and bushes and other foliage. Most have an annual life cycle. Several species are found in the area.

Blabomma californicum

Dictyna abundans

Dictyna calcarata

Dictyna cholla

Mallos mians

Mallos pallidus

Tricholathys montera

Tricholathys rothi

Yorima angelica

GENUS: Dysderidae

One species in this family is found in the area. Dysdera crocata, is a nocturnal wandering hunter, commonly found in gardens under rocks and leaf litter.  Its large chelicerae are adapted to capture its preferred prey, which gives it its common name of Sow Bug Eater. These large spiders have a dark red carapace with a pale abdomen. They use silk to spin retreats and egg sacs which the female guards. They may live two to three years.

These are medium to large wandering hunters. Primarily nocturnal, they are found under rocks and leaf litter, spending the day in a retreat under a rock or wrapped in a leaf. Cheiracanthium mildei, the Yellow Sac Spider, is one of the most common spiders found throughout Los Angeles County. It was introduced from Europe. This spider is often found wandering on the walls of houses at night and has a reputation for biting.
 

Genus: One species, Filistatinella crassipalpis, was collected in the Santa Monica Mountains.  This small spider spins a web in a crevice where it sits and waits for prey.
 

Spiders in this family are mostly nocturnal hunters, commonly found in leaf litter, in crevices of trees and under rocks and logs and sometimes found wandering in houses. They spend the day in silken retreats.  Most are mature in late spring and early summer, although some species can be found year-round as adults. Females tend to live a month longer than males in the fall. Egg sacs are attached under stones or wrapped in a leaf. Many are in the shape of a fried egg and may contain as many as 250 eggs. These spiders are small to medium, with oval elongate abdomens, and most are drab colored.  Their anterior spinnerets are large and cylindrical.  Most of the 15 genera and 25 species of Gnaphosidae in our area are native species, however one of the most common spiders in LA is an introduced species, Scotophaeus blackwalli.

 
GENERA
 
Genus:  Cesonia
Members of this genus have been collected in urban areas. These fast running hunters are usually found under leaf litter and in sandy soil. They have white bands against dark on the carapace and abdomen.
 
Genus: Drassyllus
Members of this genus are small nocturnal hunters. Two species have been collected, Drassyllus insularis and Drassyllus proclesis.
 
Genus : Gnaphosa
One species, Gnaphosa californica, has been collected. It is usually found under rocks.
 
Genus: Herpyllus 
There are several species in this genus.  Two have been collected in the area. They range from small to large and are brownish gray.
Herpyllus propinquus is one of the most common spiders in the area, often found wandering on walls in houses at night.
Herpyllus scholasticus , though less common, is also found in houses and under rocks and bark.
 
Genus: Nodocion
Two species have been collected in the Santa Monica Mountains.
Nodocion electicus  and Nodocion voluntarius
 
Genus: Scotophaeus
Scotophaeus blackwalli – An introduced species, this is one of the most common spiders in LA, found throughout the area and commonly collected wandering on walls inside houses at night. In appearance, this spider is very similar to Herpyllus propinquus.
 
Genus: Sergiolus
Members of this genus are black with white transverse bands on the abdomen and carapace. They are commonly found in leaf litter in open areas. Two species have been collected: Sergiolus angustus and Sergiolus montanus.
 
Genus: Trachyzelotes
One species, Trachyzelotes lyonneti , has been introduced from Europe. It has a cluster of stiff whiskers on the front of the chelicerae. This spider has been collected in gardens and local mountains.
 
Genus: Urozelotes 
One species, Urozelotes rusticus, has been collected.  Although widespread, most have been collected in Pasadena and Mount Washington. It is an introduced species found worldwide, usually associated with buildings. It has an elongate and pale abdomen.

Genus: Zelotes
These shiny dark black spiders are found in leaf litter and under rocks. They are usually found in open areas. Three species have been collected: Zelotes gynethus, Zelotes icenoglei and Zelotes pinos.
Heser nilicola, formerly Zelotes nilicola, is an introduced species from the Mediterranean and has been collected in houses and gardens.

Calmmaria monicae is a small spider which spins a sheet-like web with a cone shaped retreat in cavities or under rocks.

The dwarf spiders and sheet web weavers are small to very small spiders which spin horizontal sheet webs in vegetation and leaf litter near the ground and under rocks.  The larger spiders in this genus, often both male and female together, sit under the web waiting for an insect to land and then bite it from below and pull it through to wrap and eat. The very smallest spiders are more likely to be found under rocks and in leaf litter where they spin small webs. Larger species often have a pattern on the abdomen; the smallest species are usually gray or black.  Males often have weirdly shaped carapaces with eyes grouped on turrets.  These spiders are frequently collected in pit fall traps.

Genus: Erigone

Erigone dentosa

Erigone autumnalis

Genus: Ceratinops

Ceratinops palomara

Genus: Neriene

Neriene digna

Neriene litigosa

Genus: Ostearius

Ostearius melanopygius

Genus: Meioneta

Genus: Eperigone 

Eperigone eschologica

Genus: Tenuiphantes

Tenuiphantes tenuis is a new record for Los Angeles County.

The arrangement of the eyes is characteristic of the family. Four small eyes form the anterior row; two pair of larger eyes can be seen on the top of the cephalothorax.  They hunt by sight, some by day and others at night, and are extremely fast runners. Their eyesight is second only to the Jumping spiders. At night, the eyes of the Wolf Spiders will appear green in the beam of a flashlight.  They are somber colored gray or brown, often with whitish stripes on the carapace.  Most run along the ground and rest under stones.  The female carries her egg sac attached to the spinnerets until the eggs hatch.  The spiderlings then ride on their mother’s back for a week or so before dispersing.

When mating, the male approaches the female waving his pedipalps and front legs in a species-specific courtship display.

Genus: Alopecosa kochii has been collected mostly in the local mountains and adjacent areas.
 
Genus: Arctosa littoralis prefers areas adjacent to streams.
 
Genus: Pardosa
Five species of this thin-legged wolf spider have been collected. The most common is Pardosa californica.
Pardosa bellona
Pardosa californica
Pardosa ramulosa
Pardosa sternalis
Pardosa steva

Genus: Pirata
One species, Pirata sedentarius, has been collected.
 
Genus: Geolycosa 
Geolycosa gosoga – One spider has been collected in the Thousand Oaks area.

Genus: Schizocosa
Schizocosa mccooki, a large spider, has been collected along the coast from Redondo Beach to Malibu.

These mygalomorphs are among the smaller spiders in the group. They have long flexible spinnerets which they use to spin large horizontal sheet webs over holes and crevices in the banks of ravines.  One species, Megahexhura fulva, occurs in the Santa Monica Mountains.

The Pirate Spiders prey on other spiders. They have quick acting venom which is specialized to kill spiders. Web dwelling spiders are their primary prey. They approach the web and bite the resident spider on a leg before enjoying their meal. The first and second legs are armed with a row of short curved spines.

Two species, Reo eutypus and Mimetus eutypus, have been collected on plants and in houses.

One species, Oecobius navus, has been collected in the area. An introduced species, this spider is very small, oval shaped and pale gray. Often found in large numbers on the sides of buildings and along window sills. The spider spins a double sheet web and rests in between the layers. Their main prey are ants. The spider runs around the ant while surrounding it with silk. A large fringe around the anal tubercle is used to comb out the silk.

Escaphiella hespera is a very small spider usually found in leaf litter.

Lynx spiders are diurnal hunters commonly found in tall grasses and herbaceous vegetation. The elongated abdomen tapers to a point. The legs are long and covered with many erect spines, giving the spider a spiky appearance. They are sit-and-wait predators and often jump on their prey, much like the Jumping spiders. They may also stalk prey like a cat. Females lay egg sacs in the fall and remain close by until they hatch.

Genus: Peucetia
Peucetia viridans  is a large green spider collected in gardens and natural areas.
 
Genus: Oxyopes
Two species, Oxyopes salticus and Oxyopes scalaris, are smaller and less brightly colored spiders also found in gardens and natural areas.
 
Genus: Hamataliwa grisea is a cryptically colored, small spider, usually found on woody twigs and branches.

These active hunters are found along plant stems and branches. The second leg is the longest. Several species are found in the area. They are more common in natural areas around the Los Angeles basin.

Apollphanes texanus

Ebo pepinensis

Philodromus rufus pacificus

Philodromus spectabilis

Tibellus chamberlini

Tibellus oblongus

Spiders in this family include the common and ubiquitous cellar spiders which are often called daddy long legs spiders. They can be confused with Harvestmen, in the Order Opiliones, which are also called daddy long legs. The Harvestmen have one body part; the Pholcids have the two body parts typical of the spiders. Pholcids have very long, slender and flexible legs attached to a light tan body, often with darker markings. The two most common species are introduced and are found in tangled webs in the corners of houses and garages. Native species are smaller and are found under rocks and in leaf litter and debris on the ground. Females carry their egg sacs with their chelicerae until the spiderlings hatch.
 
Holocnemus pluchei and Pholcus phangioides are very common around houses. Both have been introduced from Europe.
Psilochorus utahensis are small spiders which make their webs under rocks and debris. They have been collected in natural areas.

One specimen, Prodidomus rufus, has been collected. This small spider is a nocturnal wandering hunter.     

This is the largest spider family and one of the most diverse. Spiders range from very small to large. They have the most acute eyesight of all the spider species with characteristic a pair of large anterior median eyes. They have stocky bodies with comparatively short legs. In many species the male is brightly colored while the female is more cryptically colored.

Active during the day, they stalk their prey, much like a cat.  Slowly creeping up on a fly resting on a wall, the spider will approach then jump, leaving a drag line of silk to catch itself.
 
Many Jumping Spiders in the area are native, but two species collected in the survey are new records: Plexippus paykulli and Mexigonus minutus.
 
Genus: Phidippus
Members of this genus are the largest of the Jumping Spiders. 
Phidippus audax is frequently found in gardens. This large jumper is black with three white spots on the abdomen. The chelicerae are iridescent green.   
Phidippus johnsoni has a red abdomen, sometimes with a median black stripe. The abdomen of  Phidippus adumbratus is reddish with lighter markings.
 
Genus: Habronattus
Several species of this small gray/brown spider have been collected.  Males tend to be more brightly colored than females.
Habronattus californicus
Habronattus conjunctus
Habronattus icenoglei
Habronattus schlingeri
 
Genus: The male Plexippus paykullli is a medium sized spider with white stripes on a black carapace and abdomen. Females are brownish.
 
Genus: Colonus 
Colonus hesperus is a medium sized light colored spider with large black spots on the carapace.
 
Genus: Neon
Two species, Neon avalonus and Neon ellamae, have been collected. These tiny spiders are found in leaf litter.
Several other species have been collected in the survey.
Eris militaris
Evarcha hoyi 
Marpissa robustus
Menemerus bivittatus
Metacyrba taeniolar
Metaphidippus manni
Mexigonus minutus
Mexigonus morosus
Platycryptus californicus
Pseudicius siticulosis
Sassacus vitis
Sitticus dorsatus
Terralonus californicus

This family includes the infamous Brown Recluse, which is a Midwest species not found in the Los Angeles area. A native species, Loxoceles deserta, is found in our local deserts. Four specimens have been submitted to the survey, all from Hesperia.
 
A species introduced from South America, Loxosceles laeta, has established small and localized populations in basements in downtown Los Angeles and Sierra Madre. One specimen has been collected for the survey.

Giant Crab spiders or Huntsman spiders are large brown or tan colored spiders. They are nocturnal hunters who rest in crevices and under bark during the day. They ambush and chase their prey. The front legs are held in a crab-like position, giving the spider its common name.

Genus: Heteropoda
One introduced species is occasionally found in the area.  Heteropoda venatoria, the Huntsman spider, is a large, dark spider native to the tropics. It may travel with imported fruits, especially bananas. This spider is much appreciated in the tropics where it lives in homes and preys on cockroaches at night. The female carries her egg sac in her chelicerae until the spiderlings hatch and emerge.

Genus: Olios

Olios giganticus is a native species. It is large and pale brown.

Genus: Tetragnatha
Spiders in this genus have elongate abdomens and enlarged chelicerae. Male chelicerae are greatly enlarged and armed with several large teeth. They also have a spur to hold the fangs of the female while mating. Most are found near water where they construct large orb webs at dusk each night. The orb web can be vertical to horizontal and often has an open hub. The spider can be found hanging in the middle of the web with legs outstretched. They may also rest on nearby plants with legs extended front and back in a straight line. The webs catch many flying insects, especially mosquitoes.

Three species have been collected, mostly from gardens.
Tetragnatha guatemalensis
Tetragnatha nitens
Tetragnatha versicolor

One genus, Aphonopelma.

Although no tarantulas have been collected in the survey, there are several species commonly seen in the natural areas around Los Angeles. They are our largest spiders and are dark and hairy appearing. They are also among the longest lived spiders. Female can live for many years, possibly to 30 years. Males mature at about two years of age and usually die shortly after mating.

These spiders are nocturnal sit and wait predators. They sit at the opening of the burrow and pounce at passing prey. Females may spend their entire life within the burrow. Most tarantulas seen wandering are males searching for females to mate.

Cobweb weaver is the common name for this family. They spin a sticky tangled web often found in corners of porches and under eaves. They are also called Comb-footed spiders. The last segment of the fourth leg has a comb of serrated spines which the spider uses to comb out silk into sheets to wrap around prey captured in the web. Since these spiders have weak jaws, they use their very sticky web to capture prey and then rapidly wrap the insect in sheets of silk to secure it. Only then does the spider inject its venom. Insect exoskeletons are often found intact in the web after the spider has sucked the liquefied insides. Many of the cobweb weavers have a globular shaped abdomen and are usually found hanging upside down in their webs. The Black and Brown Widows are members of this family.

Genus: Latrodectus
The spiders in this genus are the venomous widows. They are the only dangerous spiders most people will encounter in the Los Angeles area. The largest of the Theridiids, they have the characteristic globular abdomen. They spin tangled webs in which they hang upside down. Several egg sacs may be suspended within the web.

Latrodectus hesperus - The Black Widow is the best known of all the Comb-footed Spiders. Large with a shiny black spherical abdomen and a red hourglass on the underside of the abdomen, the female cannot be confused with any other spider. As juveniles, the spiders are light colored, with white, yellow and black stripes.  As the females mature, they gradually lose the coloration and become black.  The males retain the juvenile coloration.  Much smaller than the female, they are considered harmless. Once mature, they cease to spin a web. The rest of their life is spent searching for females to mate. Although the female Black Widow has a reputation for eating the male following mating, most males manage to escape unharmed. The widows are commonly found in undisturbed areas like garages, attics, and woodpiles. They are also found in local mountains where they commonly spin their webs in holes in trees and under rocky overhangs. The egg sac is a roundish brown papery case which can be seen hanging in the web; often there are several egg sacs in the web. Usually not visible during the day, this nocturnal spider moves out into the center of its web at night. The western Black Widow is a native species.

Latrodectus geometricus – The Brown Widow has been intermittently reported in Southern California since the early 1900s, however, since 2002, it has established a breeding population and has spread throughout the Los Angeles basin. Often found on fences and under patio furniture, it seems to do well in more exposed locations than the Black Widow.  The spider’s abdomen has a mottled geometric pattern which ranges from light to dark.  The hourglass is more orange than red.  The characteristic egg sac is round and cream colored and covered with spikes.

Genus: Steatoda
Spiders in this genus are very similar in appearance to the Black Widow. They are dark brown, often with a white band around the front of the abdomen. The abdomen is globular.

Steatoda grossa - The common name for this large spider is False Black Widow. It is similar to the Black Widows in shape, size and color, and is frequently mistaken for its dangerous relatives. The False Widow is dark purple brown rather than shiny black and usually has a white band around the front of the abdomen. It is considered harmless to people. An introduced species found worldwide, it is one of the most common spiders in the LA area and is usually found around houses. There are reports that the False Widow preys on the Black Widow.

Steatoda nobilis – Native to the Canary Islands, this spider was recently collected in Ventura County and is spreading throughout the Los Angeles area. It is found living in webs in the same habitats as the Brown Widow and False Black Widow. It can inflict a painful bite.

Genus: Parasteatoda

Parasteatoda tepidariorum – The Common House Spider is an introduced species found worldwide and is one of most common and numerous spiders in the area. It can be found under the eaves and window sills of most houses. Several egg sacs are usually suspended in the web with the female hanging upside down near them. The abdomen is variable, but usually light with chevron markings.

Genus: Tidarren
Spiders in this genus are very small, especially the male. The abdomen is higher than long, sometimes with a tubercle above the spinnerets. Females rest inside a curled leaf in their webs. Males amputate one of their palps before their final moult. Two species, Tidarren sisyphoides and Tidarren haemorrhoidale, have been collected in the LA basin.

Genus: Theridion
There are many species of similar appearance in this genus. These small spiders are found hanging upside down in their tangled webs. The webs are frequently found in cracks in walls and rock cliffs. Theridion melanurum, Theridion dilutum, and Theridion submissum have been collected throughout the Los Angeles area and in the local mountains. Theridion californicum, Theridion lawrencei, and Theridion punctipes/leechi have been collected only in local mountains.
 
There are numerous smaller species found in the area:
Asagena fulva
Cryptachaea blattea
Cryptachaea porter
Euryopis californica
Euryopis formosa

The front legs of these distinctive spiders are crab-like in appearance, long and angled forward. These spiders are sit and wait hunters, found in flowers, foliage and leaf litter. Their rapid acting venom is able to quickly subdue pollinating insects like bees, enabling them to safely capture prey without injury.  

Two species are commonly found in flowers. Members of both species are able to change color to match the flower they are sitting in. Misumena vatia, the Goldenrod spider, is white to yellow with reddish bands along the sides of the abdomen. Misumenoides formosipes, the Whitebanded crab spider, is similar in appearance to the Goldenrod spider, but has a white ridge along the lower edge of the carapace.

Genus: Mecaphesa

Spiders in this genus are also found sitting in flowers.  Small to medium sized, they are variable in appearance.

Mecaphesa aikoae

Mecaphesa californica

Mecaphesa importuna

Mecaphesa lepida

Mecaphesa sierrensis

Other genera of Crab Spiders are commonly found in bushes, along branches and in leaf litter. They are variable in appearance but tend to be cryptically colored.

Bassaniana utahensis

Diaea livens

Ozptyila sp.

Tmarus angulatus

Xysticus californicus

Xysticus gertschi

Xysticus goiutus

Xysticus locuples

Xysticus montanensis

Xysticus pretiosus

Xysticus punctatus

Until recently these spiders were included in the family Corinnidae.  They are active hunters, commonly found on foliage. They are pale yellow, some with darker stripes.

Meriola californica

Meriola decepta

Trachelas pacificus

These spiders are unique among the spider families in lacking venom glands. They have a cribellum, a sieve-like plate in front of the spinnerets and a comb, the calamistrum, on the fourth leg which they use to pull the silk and wrap their prey.

Genus: One species, Uloborus diversus, has been collected in the area. It has been found throughout the area in gardens. This spider spins a horizontal orb web and rests along the web with the front two legs extended. Small and pale colored, the abdomen is triangular in a lateral view, highest in the front and sloping toward the rear.

Genus: Zodarion

One specimen, as yet unidentified, has been collected in the Long Beach area.

These are large pale tan colored spiders. They are nocturnal hunters often found under rocks and in leaf litter, and frequently collected in pit fall traps.  They have been collected in natural areas a round Los Angeles.

Genus: Anachemmis 
Anachemmis linsdalei
Anachemmis sober
 
Genus: Titiotus
Titiotus schantzi

Genus: Socalchemmis
Socalchemmis cajalco
Socalchemmis gertschi
Socalchemmis icenoglei