Types of Spiders Commonly Found in California’s Sacramento Valley

The Sacramento Valley, including Fair Oaks, is home to a variety of spider species, some of which are more commonly encountered indoors. Understanding these species is the first step in effective spider control.

Black Widow Spiders (Latrodectus hesperus)

Easily identified by the glossy black body and the distinctive red hourglass marking on the underside of the female’s abdomen. Black widows are common throughout California and their venomous bite can cause severe symptoms, including muscle pain, nausea, and labored breathing. They prefer to build irregular, tangled webs in dark, undisturbed areas such as woodpiles, cluttered garages, and under eaves. While not aggressive, females will bite if they feel threatened or are protecting their egg sacs.

Brown Widow Spiders (Latrodectus geometricus)

Closely related to the black widow, brown widows are typically lighter in color, ranging from tan to dark brown, with an orange or yellow-orange hourglass marking. A key identifier is their spiky, round egg sacs, unlike the smooth sacs of black widows. While their venom is less potent than the black widow’s, a bite can still cause pain and a red mark. They are often found in outdoor structures, under eaves, and in cluttered areas around homes in Fair Oaks and Orangevale.

Wolf Spiders (Family Lycosidae)

These are large, robust, hairy spiders, typically brown or gray with various markings. Unlike many other spiders, wolf spiders do not spin webs to catch prey. Instead, they are active hunters, relying on their speed and excellent eyesight to pursue insects on the ground. They are often found in gardens, leaf litter, and can quickly enter homes in search of prey or shelter, particularly in areas like Carmichael and Gold River. While their bite can be painful, it is generally not dangerous to humans.

Yellow Sac Spiders (Cheiracanthium inclusum)

These small, pale yellow or beige spiders have long, slender legs and are nocturnal hunters. They do not build large, intricate webs but instead create small silken sacs for resting or laying eggs, often found in corners of rooms, behind pictures, or under furniture. Their bites, though not highly toxic, can be painful and cause redness, swelling, and itching. They are a common indoor spider in Fair Oaks and surrounding communities.

Cellar Spiders (Family Pholcidae)

Often referred to as “daddy long-legs,” cellar spiders have small bodies and extremely long, thin legs. They construct loose, irregular webs in damp, dark, and undisturbed areas such as basements, crawl spaces, and garages. While they may appear intimidating due to their size, they are harmless to humans and play a role in controlling other insects and spiders.

Orb Weaver Spiders (Family Araneidae)

These spiders are known for their classic, intricate, wheel-shaped webs, often seen suspended between branches, shrubs, or structures. They vary widely in appearance but are generally harmless, focusing on catching flying insects. While primarily outdoor spiders, they can build webs near entry points of homes in areas like Folsom and Roseville, sometimes venturing inside.