Common Spiders in San Diego to Watch Out For

Common Spiders in San Diego to Watch Out For

San Diego County is home to a huge variety of plant and animal life. Unfortunately, some of that wildlife is dangerous to humans; and some of it is close to home. We’re talking about the eight-legged menaces of the arachnid world. The black widow, the brown widow, and the desert recluse are San Diego’s three most infamously dangerous species of spider.

If you spot any of these little nuisances on your property or in your home, call Joshua’s Pest Control right away to have an expert come out and survey the infested area before a serious bite puts a major damper on your summer barbeque.


The most common poisonous spiders we see in San Diego are black widow, brown widow, and desert recluse spiders.

Black Widow Spiders

These vicious arachnids get their name from their sinister post-mating habits. After successfully mating with a male, the female black widow will attack and eat the male, potentially to benefit the offspring. It’s this female’s bite that packs the well-known venom. The males, by contrast, have a very weak level of venom in their bites.

The neurotoxic venom of a black widow affects some core body functions, including the way cells communicate with one another, and it can cause nausea and muscle pain. In high doses, this can lead to significant medical problems, including mental retardation, dementia, and amnesia. However, since most bites are treated in time, fatalities by this neurotoxin are rare. Still, the affects of the toxin can drastically reduce the health of young children and the elderly.

The black widow is identified most easily by the red hourglass shape on the bottom of its posterior body segment. This mark isn’t found on the shiny topside, so the spider has to be inverted for its markings to be visible.

These spiders are found either outdoors in sheds and under rocks and woodpiles, or in quiet indoor places like your basement or attic. If you spot a black widow in your home or on a part of your property you use often, call Joshua’s Pest Control and a spider expert will be there to rid your home of this dangerous pest.


Brown Widow Spiders

Predominantly found in the southern half of the United States (including San Diego County), the geometric button spider, or brown widow, is closely related to the famed black widow, and packs equally serious venom.

The brown widow is usually tan, grey, or rust-colored with an orange hourglass shape on its largest body segment. This spider also keeps a very recognizable egg sack that looks like a small, tan, spiky ball. It takes 20 days for the eggs to hatch, so if you spot these round, pointy egg sacks call Joshua’s Pest Control experts immediately to prevent these spiders from hatching and making life more difficult for your barbeque guests.

Though it’s more likely you’ll find them outdoors, they could easily invade your basement or other areas where you’d least expect them to be. Use caution when in areas that haven’t been cleaned in a while, or appear dark and full of spider webs.


Desert Recluse Spiders

Though often confused with the more renowned brown recluse spider, the desert recluse also uses necrotizing venom to repel predators.

Necrotic venoms affect the tissues on the body by essentially destroying them. One small bite can cause a lesion, sore, or crater-like wound on the bite site. In some cases, victims must seek serious medical attention to repair the affected area. Necrosis can be fatal in extreme cases, though this is rare when induced from the venom of a spider bite.

This is different from a black widow bite in one key way: the black widow’s venom attacks your nervous system, the recluse’s venom eats away at your tissue.

Moreover, desert recluse spiders aren’t aggressive, and their bites occur in defense of their own well-being. If your property is strewn with these spiders, it’s possible they could get into your beach blankets, tents or clothing, where they can become trapped and bite the first part of your body that comes in contact.

Are Brown Recluses Found in San Diego?

Although there are occasional reports of brown recluse bites, brown recluses are typically not found in San Diego. 

If you believe you have been bitten by any one of these spiders, contact a healthcare provider immediately. If you’d like to take preventative measures against these pests, call Joshua’s Pest Control and speak to an expert today.


Photo Credit: OakleyOriginals