About Spiders in California

With over 50,000 spider species worldwide, it's no wonder that this enormous group of arachnids has managed to find a way to survive in every conceivable habitat: spiders can be found in the Arctic, in deserts and even underwater.
California is home to thousands of types of spiders. They range from small to large, venomous to harmless, and ones that hunt with or without a web.

History

The majority of spiders found in California are foreign invaders. Some of the largest populations of California spiders came from South America, the Mediterranean region, Australia, New Zealand and Europe.

Types

While there are thousands of types of spiders in California, the most common include the following: tarantulas, calisoga spiders, grass spiders, sow-bug killers, daddy long-legs, black widows, American house spiders, garden spiders, wolf spiders and jumping spiders.

Geography

Spiders thrive in a tremendous variety of habitats. Some, like the calisoga spider, prefer the dry Oakland hills region; others can be found only under wood or bark and still other spiders are found exclusively in urban areas. Tarantula females live in burrows underground and can often accidentally dug up by people working in their gardens or backyards. The grass spider prefers to spin its web on fence posts and street signs.

Misconceptions

Most people think that spiders are easily identified by comparing them to pictures in books or on the Internet; unfortunately, in most cases, nothing could be further from the truth. While some spiders, such as the black widow, have very distinct colors and markings, most spiders vary widely in looks within their own particular species and family. Correctly identifying a spider can often be extremely difficult.
A perfect example of this is the brown recluse spider. Many people believe that the brown recluse is the most dangerous spider in California. However, the brown recluse is actually native to certain Southern states and does not live in California at all; what many Californians take to be a brown recluse is actually a close cousin.

Warning

While the bite of jumping spiders, wolf spiders, tarantulas and hobo spiders may be painful and cause some uncomfortable symptoms, the only spider in California with medically significant venom is the black widow. Black widows prefer to live in dark places such as closets, attics and garages. They are present throughout California, but especially in the warmer regions of the state. It has been over a decade since a person died from a black widow bite since physicians have highly effective ways of treating bite victims. However, a black widow bite can pose a serious threat to young children or the elderly. If you believe someone has been bitten by a Black widow and they are experiencing symptoms such as severe muscle cramps, abdominal pain, nausea, vomiting or fainting, seek medical help immediately.

Resources

• Information and pictures of California spiders