Below are pictures and descriptions of the most common spiders you may encounter in and around your home or office. Click any picture to enlarge. You’ll find a DO-IT-YOURSELF self help section at the end of each description. NOTE: ALL SPIDER ARE VENOMOUS. USE CAUTION WHEN HANDLING. Spiders use venom to paralyze their prey long enough to wrap them in silk. This allows the spider to store them alive since spiders only eat live prey.
Black Widow Spider
The Black Widow spider is very common in our area. There are two others in the same family, the Brown Widow, most common and the Red Widow, not as common. All three are found in and outside our homes or offices. They are medium sized by comparison to others with an adult diameter of about 1.25″. They build a messy web and it nearly always contains eggs which looks like a spiny ball. The widow spider gets her name from killing the male after procreation and eating them. The hourglass marking on their belly is the most common way of identifying them. The Red Widow has a striped abdomen. Of all the local spiders, this group is the most dangerous. Though their venom is more potent than a rattlesnake, the amount is very small. Biting a human is purely in self defense as they are not aggressive. We find them mostly in pool cages below the center support rib and around the garage door frames. DO-IT-YOURSELF: Vacuum up the spider and their web and apply a pryrethroid insecticide to the area to repell the insects they are attracted to.
Brown Recluse Spider
The Brown Recluse Spider is not in our area but listed in our library because of it’s reputation of being in our area. See the CDC’s confirmed distribution in our library. It is a small spider. An adult is about 1″ in diameter. The most notable marking for identification is the violin shaped marking on their cepholothorax. However, many spiders have a similar marking. Second confirmation and unique only to the Brown Recluse is the eyes. It has 3 pairs of eyes across the top of it’s head. Left, right and center. The eyes are very small and each pair is so close that to the naked eye, it may look like 3 eyes rather than 3 pairs. It is the most venemous spider in the US at this time. DO-IT-YOURSELF: Read all you can, because you’re not going to find them here.
Brown Recluse Spider Distribution
This chart represents the confirmed distribution of the Brown Recluse spider as reported to the CDC in Atlanta. As you can see, this spider is not in the bay area. We receive many calls throughout the year claiming they were bitten by a Brown Recluse spider as confirmed by their doctor. First, unless you’ve traveled to these areas or had visitors from these areas, it’s not from a Brown Recluse. Other spiders pack a good punch, but do not live up to the devestation of the Brown Recluse spider.
Spider Bite Diagnostic Chart
We receive many calls annually claiming they’ve been bitten by a spider. This is a chart of the progression of a spider bite. This chart is based on the Brown recluse spider which is not in our area, but other spiders could have similar reactions. Note: I’ve been clothes lined by webs, crawl through attics draped in spider webs and under homes that look like a creature feature movie and have yet to be bitten and neither have any of our technicians. Though there are spider bites, most of what I investigate is not.
Green Lynx Spider
The Green Lynx spider is very common in our rural areas. They are rarely seen inside. When inside they are usually on a plant being transported in and out. They are medium sized with the adult being about 3/4″ in diameter. They are an ambush predator and do not build webs. DO-IT-YOURSELF: Since this spider relies on the green background to ambush their prey, eliminate green things, especially around windows and doors. If you transport plants in and out, apply a little soapy water the foilage about a half hour before bringing the plant inside.
Golden Silk Spider
The Golden Silk spider is very common outside and I’ve never seen any inside. They are sometimes found in pool cages. They are a very large and colorful spider. A full grown adult is about 5″ in diameter. They are an orb weaver creating a very large round radial spoked web. I’ve seen the radial areas as much as 5′ in diameter with attaching points 10′ away. Their web is so strong, they’ll nearly knock you off your feet when you run into them. Due to their size, they eat very large pests like dragon flies, butter flies, moths, lizards, frogs, etc. DO-IT-YOURSELF: Leave them alone, they help balance nature outside.
Common House Spider
The common house spider is a very small spider and as the name implies, they are very common. The adult spider is about 1/2″ in diameter. Their web is messy. We find them mostly inside homes around the kick plates of kitchen cabinets and below furniture. They feed on very small prey like springtails, gnats and small ants. DO-IT-YOURSELF: Vacuum the spider and web and apply a pyrethroid insecticide to the area to repell the pests they are attracted to.
Southern House Spider
There are a few spiders in this group. They can be fairly large, up to 2″ in diameter. They spin a messy web to catch their prey. They are found inside and outside usually tucked into a corner. They feed on any moving pest that comes near or into their web. DO-IT-YOURSELF: Vacuum the web and spider and apply a pyrethroid insecticide in the area. This does nothing to the spider except repell it’s food source from the area.
The Huntsman spider is one of the largest spiders in our area. They are very common in and outside our homes and offices. The largest adult I’ve seen is about 6″ in diameter. They feed on larger prey. They have spinerettes , but do not build webs. They ambush their prey. This spider can run amazingly fast and jump large distances. We receive many calls annually confusing this spider with the Brown Recluse spider. It does have a marking on it’s cepholothorax similar to a violin, but it’s amazing size eliminates this thinking. They run across ceilings and jump from furniture. They are so large, you can hear them running and landing. They are very commonly found in the attic and crawls. DO-IT-YOURSELF: This spider feeds on large prey. Without a web, they can be found anywhere. Best approach is eliminate their food source which is usually roaches or carpenter ants.
Regal Jumping Spider
The Regal Jumping spider is an interesting fuzzy little spider. They are small to medium in size with an adult being about 1/2″ in diameter. They have spinerettes but do not build webs, they ambush their prey. I’ve seen them stand on their hind legs and spin their front legs like a karate move. Their jump is rather small, possibly an inch or so. They feed on small crawling insects. DO-IT-YOURSELF: Since this pest does not build a web, they randomly appear. Take it outside and release it or if you must, smack it.
Spinybacked Orb Weaver Spider
The spiny backed orb weaver is one of the more interesting looking spiders. They are very common in our area. The largest one I’ve ever seen is about 1/2″ in diameter. They are an orb weaver, spinning a circular web with radial spokes with this circlular part about 2′ in diameter. We find them mostly inside pool cages along the top and sides and never inside the home. They feed on flies, mosquitos, gnats, small butterflies and other small pests. DO-IT-YOURSELF: Inside the pool cage, sweep them down. We’ve not found anything that keeps them away. Outside, leave them alone. They’re doing they’re job to keep nature in balance.
Tropical Orb Weaver Spider
The Tropical Orb weaver spider is a fairly large spider. Stretched out, an adult is about 2″ in diameter. I’ve never encountered them inside a home. They are an orb weaver meaining they spin the circular web with radial spokes. The circular part of the web is about 2′ in diameter but can have attaching points several feet away. They are found between trees and catch bugs, lizards and frogs. DO-IT-YOURSELF: Leave them alone, they are keeping nature in balance outside.