COMMON SYNANTHROPIC SPIDERS IN CALIFORNIA

Pholcus phalangioides
Family Pholcidae
"Daddy long-legs," "cellar spider"

The common synanthropic cellar spiders in California are European invasives, native pholcids are much smaller.  Pholcus can be distinguished from Holocnemus by the grey/brown concolorous abdomen.  Their webs are irregular tangles.

Photo © Jerome Rovner HAVE PERMISSION
pholcus

Steatoda grossa
Family Theridiidae
"False black widow"

Another European invasive, this spider seems to be displacing our native black widows in urban areas.  This spider is roughly the same size and shape as a black widow, but is brown with a faint purple sheen.  Makes a typical theridiid tangle web.

Photos
Top
© Jim Berrian HAVE PERMISSION
Bottom © Cheryl Moorehead  HAVE PERMISSION
steatoda
steatoda
Araneus diadematus
Family Araneidae
"Cross orbweaver," "Garden spider"

Another European invasive, this spider can become quite imposing in size and density in the late fall.  Makes a large vertical orb-web.

Photo © Diogo Verissomo HAVE PERMISSION
diadematus
Argiope aurantia
Family Araneidae
Yellow garden spider, "Yellow argiope"

Common in gardens, makes an orb web with shiny, radiating "stabilimenta" (sing. stabilimentum).

Photo by Jo-Ann Ordano
© California Academy of Sciences HAVE PERMISSION
a aurantia
Zygiella x-notata
Family Araneidae

Another common invasive, this spider makes a vertical orb web with two sectors missing, looking like a pizza with a single piece missing.

Photo © Ian Pembroke NEED PERMISSION
zygiella
Grass spiders
Family Agelenidae

Photo
Top © Ray A. Akey NEED PERMISSION
Bottom © Marion Cronen HAVE PERMISSION
hololena
agelenid

Badumnas longinqua
Family Desidae

This invasive spider is native to Australia and New Zealand.  The web is a mesh, often with a distinct lattice pattern, commonly seen on fenceposts, streetsigns, and sideview mirrors.

Photo cc Stephen Lew Attribution-NonCommercial 2.5
badumnas
Wolf spiders
Family Lycosidae

Wolf spiders are difficult to id even to genus without a microscope, but most found around homes turn out to be in the genus Pardosa.  Females are often seen carrying their eggsacs on their spinnerets, or carrying spiderlings on their backs.  Wolf spiders do not make a web, except for the infrequently seen Sossipus which makes a sheet web.

Photos
Top © Lynette Schimming HAVE PERMISSION
Bottom © Joyce Gross
lycosidae
lycosidae

Zoropsis spinimana
Family Zoropsidae

A recently arrived mediterranean invasive, now found in the Bay Area.  If you see this spider, please contact Darrell Ubick at the California Academy of Science.  This spider does not make a web.

Photos
Top (female) cc Anca Mosoiu
Attribution-NonCommercial 2.5
Bottom (male) © Flickr user Omeuceu NEED PERMISSION
zoropsis
zoropsis
Cheiracanthium spp.
Family Miturgidae
"Yellow sac spider"

Cheiacanthium inclusum (pictured) is common in agricultural settings, and C. mildei is common in homes.  They are annecdotally associated with mildly symptomatic envenomations, but there are no studies or data supporting this.  Yellow sac spiders do not make a web but may make a conspicuous molting chamber.

Photos © Jim Berrian  HAVE PERMISSION
Cheiracanthium
cheiracanthium
Misumena vaita
Family Thomisidae

Photo cc Stephen Lew Attribution-NonCommercial 2.5
misumena
Phidippus spp.
Family Salticidae

There are many jumping spiders around the home and garden, but of the common ones Phiddipus are the most conspicuous.  They do not make a web.

Photos
top (P. johnsoni) © I. R. Lindsey NEED PERMISSION
bottom (P. audax)
© Tom Murray  HAVE PERMISSION
phidippus johnsoni
phidippus audax