Poisonous Spiders
Black widow spiders reside throughout California. Their bites cause serious medical reactions including muscle cramps, nausea, weakness and breathing difficulties. Identify black widow spiders by the red hourglass mark on the shiny, black body. Expect less serious symptoms if bitten by a northwestern brown spider (hobo spider). There is no special treatment for spider bites. Keep the wound clean and consult a physician if an infection develops. The most poisonous spider, the brown recluse, is not found in California.
House Spiders
Commonly known as American house spiders, these brown arachnids comprise a variety of spider types in California. They reside in closets, corners, behind walls and under furniture. Jumping spiders produce a scare but are relatively harmless. Shake out linens before using and wipe down the insides of boots before stepping into them. Common outdoor spiders also find their way into homes. To reduce entry points into your house, caulk any gaps around the foundation and windows.
Garden Spiders
Funnel web weaver spiders, commonly called grass spiders, build sheet webs in grass and shrubs. These grass spiders hide from prey in the funnel spun on the side of the web. Female grass spiders are larger and more colorful than the males. Orb weaver spiders comprise hundreds of species in California. Their spiral webs radiate out from center support lines. The calisoga spider thrives in the hills near Oakland. They look similar to the California tarantula but have shorter hairs.
Wolf Spiders
Wolf spiders are one of the most common spiders found in California. They do not construct webs. Wolf spiders measure up to 4 inches and burrow into sand or leaves. Tarantulas also burrow into the ground. California residents often find tarantulas while digging in the yard. Nocturnal hunters, their hairy bodies are sensitive to any movement. These sharp bristles shed easily and cause skin and eye irritation. Wash hands thoroughly after touching a tarantula.