Spider Identification: Common Southern California Spiders

There are currently over 40,000 recorded spider species in the world with about 3,400 residing in North America. Spiders are characterized by eight legs and two main body segments. As scary as spiders might look, most are quite harmless and nonaggressive. In fact, many are helpful to ecology and social order by controlling the populations of pesky insects.

That said, spiders are still not welcome guests in our homes. Aside from bites, most spiders naturally create webs that can be bothersome, and no homeowners want to deal with an outbreak of spider babies.

If you’ve been finding spiders around your home, use our guide to see if you can identify them.

Cellar Spider (Pholcus phalangioides)

Cellar spiders, skull spiders, daddy long legs—these spiders go by various names. They are very common household spiders found all over the world, primarily in warm areas as they are incapable of surviving in cold weather. They are known for their small bodies and long, thin legs that are about five or six times the length of their bodies. They are known for living on the ceilings of garages, rooms, and cellars, explaining one of its common names.

Cellar spiders are considered beneficial because they prey on pests like mosquitos and other insects. They are also known to kill and eat other spiders, some of which are highly venomous to humans, such as redback and hobo spiders. These spiders are much larger and more aggressive than daddy long legs, which has led to the misconception and false urban legend that cellar spiders are the most venomous spiders in the world.

Common House Spider (Parasteatoda tepidariorum)

The common house spider, which is internationally known as the American house spider, exclusively benefits from humans and usually builds its web in or near human buildings. They tend to be a dull brown color in appearance with an average body size of a quarter inch long and an inch across, allowing them to blend into background quite easily.
The common house spider primarily feeds on insects and other small invertebrates that are considered pests, including ants, flies, mosquitoes, and wasps. For prey that is too agile, the spider will actually shoot its web to catch the escaping prey and reel the thread in. Larger females can also eat small lizards.

As they live near humans, common house spiders are not aggressive and will even let humans approach their webs. However, if they feel threatened, they will bite in self-defense, but the bite is as painful as a bee sting. While females can deliver venom, the venom is not potent enough to do much of any harm.

Barn Funnel Weaver (Tegenaria domestica)

As you can probably guess from “domestica,” barn funnel weavers are common household spiders that inhabit all areas of the world. A barn funnel weaver possesses an elongated body, flattened cephalothorax, and straightened abdomen. Coloration is typically dark orange to a grayish brown or beige with stripes down the legs.

These spiders weave funnel-shaped webs to catch their prey. The webs usually consist of numerous silk threads spun over a flat surface with a funnel structure reaching for the corner where the spider usually resides.

Barn funnel weavers are not an aggressive species and are more likely to retreat or even play dead if threatened by larger creatures. They rarely bite, but when they do, the bite is painless. In fact, these spiders can be quite docile, enough that they can be manipulated, caught, or taken away from their webs without any aggressive behavior.

Brown Widow (Latrodectus geometricus)

A “cousin” to the more widely known black widow, brown widows are generally lighter in color, ranging from tan to dark brown to black. Like the black widow, brown widows have the trademark hourglass-shaped marking on their undersides, though these markings tend to be a bright orange or yellow instead of red.

In Southern California, brown widows are more common than black widows. In fact, in the city of San Diego, you might find as many as 20 to 30 brown widow spiders in your backyard. Brown widows are actually competing with and pushing out native black widows.

Brown widows have neurotoxic venom that is just as potent as the black widow’s. However, research shows that a brown spider bites are not dangerous or lethal and no more painful than bites from common house spiders. Some researchers claim this is because brown widow venom is confined to the bite area and surrounding tissue. Others suggest that brown widows are incapable of delivering the same amount of venom as a black widow.

Have you seen any of these spiders lately? Like we said, most of these spiders are harmless for the most part, but the last thing you want is for a spider, which can turn into several, to set up camp in your home. If you’re especially squeamish about spiders or unsure of what you’re dealing with, be sure to give us a call.

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